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.
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| # | 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. | 適應輻射 | 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. | 人口分散 | 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. | 耐环境性 | 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. | 限制因素 | 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. | 生物因子 | 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. | 非生物因子 | 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. | 捕食者与被捕食者的关系 | 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. | 營養級 | 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. | 能源金字塔 | 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. 生物量 2. 生物质 | 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. | 营养循环 | 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. | 氮循环 | 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. | 生态位 | 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. | 栖息地破碎化 | 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. | 入侵物種 | 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. | 关键物种 | 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. | 保护生物学 | 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. | 恢复生态学 | 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. | 生态恢复力 | 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. | 生态演替 | 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. 摩爾 2. 摩尔 | 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. | 摩爾質量 | 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. | 1. 實驗式 2. 最簡式 | 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. | 1. 分子式 2. 化学式 | 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. | 化學計量學 | 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. | 化学方程式 | 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. | 化学计量系数 | 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. | 反应混合物 | 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. | 質量守恆 | 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. | 限制反应物 | 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. | 过量的反应物 | 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. | 理论产量 | 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. | 实际产量 | 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. | 产率百分比 | 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. | 溶解度 | The solubility of many solids increases as water warms. |
Vocabulary reading and practice
Page 9 vocabulary review
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English reading
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Vocabulary quiz
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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).