English Vocabulary · Grade 9 Live Review Preview
9th Grade Vocabulary Words
Ninth grade marks the transition to high-school reading and writing across literature, argument, research, biology, physical and Earth science, algebra, computing, world history, civics, and geography. This level develops precise academic and domain-specific vocabulary while strengthening context, nuance, source evaluation, figurative language, and evidence-based communication.
This independently authored 800-word beta curriculum is arranged in twenty-three pages of up to thirty-five words. Pages containing words 1–500 include five cloze questions drawn only from that enhanced range; words 501–800 remain fully visible and editable as list pages while the expanded practice layer is developed. Each row includes a subject-field label and an editable word-study note about a transparent affix, compound structure, capitalization, or dictionary base form. The cited Grade 9 resources calibrate difficulty and study skills only; all learner-facing definitions, examples, quizzes, and descriptions are original KSSR copy.
Please note: the vocabulary lists for grades 9~11 have been selected to ensure no overlap with the previous grade level. If the words are too specialized or difficult for you, please go back to grade levels 4~8 and review the words on those pages.
Open the basic text version — works without JavaScript and is suitable for printing.
Your private study tools
Track your learning with My Vocabulary
Use the three small controls beside any word. Your choices stay attached to your account and appear in your My Vocabulary record.
- Star a difficult word to practise it again.
- Check a word when you have learned it.
- Add a note with a memory clue, synonym, or reminder.
These controls work during your free visits and save privately on this browser. Sign in to move them into your account’s My Vocabulary record.
| # | Word | Details | Meaning | Sample sentence |
|---|---|---|---|---|
| 281 | adaptive radiation | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: adaptive + radiation. Study the complete expression as one field-specific unit. | bức xạ thích ứng | Island finches underwent adaptive radiation as they used different foods. |
| 282 | population dispersion | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: population + dispersion. Study the complete expression as one field-specific unit. | sự phân tán dân số | Nesting seabirds show clumped population dispersion along the cliffs. |
| 283 | environmental resistance | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: environmental + resistance. Study the complete expression as one field-specific unit. | sức đề kháng môi trường | Disease and food shortage contribute to environmental resistance. |
| 284 | limiting factor | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: limiting + factor. Study the complete expression as one field-specific unit. | yếu tố hạn chế | Available nesting space is the limiting factor for the colony. |
| 285 | biotic factor | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: biotic + factor. Study the complete expression as one field-specific unit. | yếu tố sinh học | Competition with an invasive plant is a biotic factor. |
| 286 | abiotic factor | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: abiotic + factor. Study the complete expression as one field-specific unit. | yếu tố phi sinh học | Soil pH is an abiotic factor affecting which plants can grow. |
| 287 | predator-prey relationship | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: predator + prey + relationship. Study the complete expression as one field-specific unit. | mối quan hệ động vật ăn thịt-con mồi | Changes in snowshoe hare numbers affect their predator-prey relationship with lynx. |
| 288 | trophic level | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: trophic + level. Study the complete expression as one field-specific unit. | cấp độ danh hiệu | An herbivore occupies a lower trophic level than a hawk. |
| 289 | energy pyramid | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: energy + pyramid. Study the complete expression as one field-specific unit. | kim tự tháp năng lượng | The energy pyramid is widest at the producer level. |
| 290 | biomass | noun StudyField: Grade 9 life-science and ecology term Word study: Base-form focus: biomass is the dictionary headword; compare its inflected or derived forms in context. | 1. sinh khối 2. sinh khối loài 3. chất | The grassland contains more plant biomass than wolf biomass. |
| 291 | nutrient cycle | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: nutrient + cycle. Study the complete expression as one field-specific unit. | chu trình dinh dưỡng | Decomposers return matter to the soil in a nutrient cycle. |
| 292 | nitrogen cycle | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: nitrogen + cycle. Study the complete expression as one field-specific unit. | chu trình nitơ | Bacteria convert atmospheric nitrogen during the nitrogen cycle. |
| 293 | ecological niche | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: ecological + niche. Study the complete expression as one field-specific unit. | hốc sinh thái | Two species with an identical ecological niche compete strongly. |
| 294 | habitat fragmentation | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: habitat + fragmentation. Study the complete expression as one field-specific unit. | sự phân mảnh môi trường sống | A highway caused habitat fragmentation in the forest. |
| 295 | invasive species | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: invasive + species. Study the complete expression as one field-specific unit. | loài xâm lấn | The invasive species crowded native mussels off the rocks. |
| 296 | keystone species | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: keystone + species. Study the complete expression as one field-specific unit. | loài chủ chốt | Sea otters are a keystone species because they limit sea urchins that consume kelp. |
| 297 | conservation biology | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: conservation + biology. Study the complete expression as one field-specific unit. | sinh học bảo tồn | Conservation biology guides plans for reconnecting wildlife habitat. |
| 298 | restoration ecology | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: restoration + ecology. Study the complete expression as one field-specific unit. | phục hồi sinh thái | Restoration ecology informed the replanting of native wetland grasses. |
| 299 | ecological resilience | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: ecological + resilience. Study the complete expression as one field-specific unit. | khả năng phục hồi sinh thái | Species diversity can strengthen ecological resilience after drought. |
| 300 | ecological succession | noun StudyField: Grade 9 life-science and ecology term Word study: Term structure: ecological + succession. Study the complete expression as one field-specific unit. | diễn thế sinh thái | Ecological succession began when lichens colonized the bare lava. |
| 301 | mole | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Base-form focus: mole is the dictionary headword; compare its inflected or derived forms in context. | 1. mol 2. chắn 3. sóng | One mole of carbon atoms contains Avogadro's number of atoms. |
| 302 | molar mass | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: molar + mass. Study the complete expression as one field-specific unit. | khối lượng mol | Water has a molar mass of about eighteen grams per mole. |
| 303 | empirical formula | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: empirical + formula. Study the complete expression as one field-specific unit. | công thức thực nghiệm | The empirical formula of hydrogen peroxide is HO. |
| 304 | molecular formula | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: molecular + formula. Study the complete expression as one field-specific unit. | công thức phân tử | The molecular formula of hydrogen peroxide is H2O2. |
| 305 | stoichiometry | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Root and suffix focus: -metry relates to measuring. | 1. Phép 2. tỷ lượng 3. tính | Stoichiometry predicts how much oxygen is needed to burn the fuel completely. |
| 306 | chemical equation | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: chemical + equation. Study the complete expression as one field-specific unit. | phương trình hoá học | The balanced chemical equation has the same number of each atom on both sides. |
| 307 | stoichiometric coefficient | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: stoichiometric + coefficient. Study the complete expression as one field-specific unit. | hệ số cân bằng hóa học | The stoichiometric coefficient 2 indicates two molecules of water. |
| 308 | reaction mixture | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: reaction + mixture. Study the complete expression as one field-specific unit. | hỗn hợp phản ứng | The reaction mixture turned cloudy as a solid formed. |
| 309 | conservation of mass | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: conservation + of + mass. Study the complete expression as one field-specific unit. | bảo toàn khối lượng | Conservation of mass requires the total reactant mass to equal the total product mass in a closed system. |
| 310 | limiting reactant | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: limiting + reactant. Study the complete expression as one field-specific unit. | hạn chế chất phản ứng | Hydrogen was the limiting reactant, so some oxygen remained. |
| 311 | excess reactant | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: excess + reactant. Study the complete expression as one field-specific unit. | chất phản ứng dư thừa | Oxygen was the excess reactant and remained after the hydrogen was consumed. |
| 312 | theoretical yield | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: theoretical + yield. Study the complete expression as one field-specific unit. | năng suất lý thuyết | The calculation gave a theoretical yield of twelve grams. |
| 313 | actual yield | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: actual + yield. Study the complete expression as one field-specific unit. | sản lượng thực tế | Some product was lost during filtering, so the actual yield was ten grams. |
| 314 | percent yield | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: percent + yield. Study the complete expression as one field-specific unit. | phần trăm năng suất | The experiment's percent yield was eighty-three percent. |
| 315 | solubility | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Suffix focus: -ity commonly forms a noun naming a quality, state, or condition. | 1. Tính 2. hoà tan 3. được | The solubility of many solids increases as water warms. |
Vocabulary reading and practice
Page 9 vocabulary review
Review five selected words from page 9.
English reading
Reading passage is being prepared.
Vietnamese translation
A reviewed translation is not available for this passage yet.
Vocabulary quiz
Choose the dictionary equivalent for each of 5 selected words.
Vocabulary chart page
This page focuses on the word chart. Reading passages appear once in each three-page group, while cloze quizzes remain in the established enhanced range for this level.
Sources and curriculum references
These references guide selection and calibration. Definitions, sample sentences, readings, questions, and teaching notes are independently written and reviewed.
- GreatSchools: 9th Grade Vocabulary Words
- Victoria University of Wellington: Coxhead Academic Word List
- Common Core: Language Standards for Grades 9–10
- Common Core: Science and Technical Subjects, Grades 9–10
- WikDict downloadable bilingual dictionaries
- Kaikki.org / Wiktextract machine-readable Wiktionary data
- Language-Learning-decks public flashcard datasets
- SBBIC English-to-Khmer Dictionary
- English–Khmer Dictionary Dataset (machine-generated Khmer fallback; human review required)
- PanLex meanings snapshot (direct CC0 gap candidates; human review required)
- Cambridge bilingual dictionaries (individual editorial sense checks)
- Collins English–Hindi Dictionary (individual editorial checks)
- Hindwi and Rekhta dictionaries (individual Hindi/Urdu checks)
- National Institute of Korean Language: Basic Korean Dictionary
- JMdict/EDRDG Japanese dictionary project
- CC-CEDICT Chinese dictionary project
- VDict Vietnamese Dictionary (individual editorial check)
- Google Translate (machine-assisted lesson-reading draft; fluent review required)
- Kuperman et al.: Age-of-acquisition ratings for 30,000 English words
- The Princeton Review, Word Smart (2006 and 2012 editions; bibliographic calibration only).

