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 |
|---|---|---|---|---|
| 386 | mantle plume | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: mantle + plume. Study the complete expression as one field-specific unit. | អាវធំ | A mantle plume may supply magma to the hotspot. |
| 387 | P wave | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: P + wave. Study the complete expression as one field-specific unit. | រលក P | The P wave arrived before the other seismic waves. |
| 388 | S wave | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: S + wave. Study the complete expression as one field-specific unit. | រលក S | The absence of an S wave through the outer core helped reveal that the layer is liquid. |
| 389 | rain shadow | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: rain + shadow. Study the complete expression as one field-specific unit. | ស្រមោលភ្លៀង | The desert lies in a rain shadow beyond the coastal mountains. |
| 390 | drainage basin | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: drainage + basin. Study the complete expression as one field-specific unit. | អាងបង្ហូរទឹក | Pollution upstream can affect the entire drainage basin. |
| 391 | climate system | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: climate + system. Study the complete expression as one field-specific unit. | ប្រព័ន្ធអាកាសធាតុ | The climate system transfers heat through winds and ocean currents. |
| 392 | positive feedback | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: positive + feedback. Study the complete expression as one field-specific unit. | មតិស្ថាបនាវិជ្ជមាន | Melting ice creates positive feedback because darker water absorbs more sunlight. |
| 393 | negative feedback | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: negative + feedback. Study the complete expression as one field-specific unit. | មតិប្រតិកម្មអវិជ្ជមាន | Heat loss from warmer Earth acts as a negative feedback. |
| 394 | carbon sink | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: carbon + sink. Study the complete expression as one field-specific unit. | លិចកាបូន | A growing forest can function as a carbon sink. |
| 395 | albedo | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Base-form focus: albedo is the dictionary headword; compare its inflected or derived forms in context. | អាល់បេដូ | Fresh snow has a high albedo. |
| 396 | ocean acidification | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: ocean + acidification. Study the complete expression as one field-specific unit. | ការធ្វើឱ្យអាស៊ីដនៃមហាសមុទ្រ | Ocean acidification makes shell building harder for some organisms. |
| 397 | sea-level rise | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: sea + level + rise. Study the complete expression as one field-specific unit. | ការកើនឡើងកម្រិតទឹកសមុទ្រ | Sea-level rise increases coastal flood risk. |
| 398 | ecological footprint | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: ecological + footprint. Study the complete expression as one field-specific unit. | ដានអេកូឡូស៊ី | Eating less resource-intensive food can reduce an ecological footprint. |
| 399 | resource depletion | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: resource + depletion. Study the complete expression as one field-specific unit. | ការថយចុះធនធាន | Overpumping groundwater causes resource depletion. |
| 400 | environmental justice | noun StudyField: Grade 9 physical, Earth, and environmental-science term Word study: Term structure: environmental + justice. Study the complete expression as one field-specific unit. | យុត្តិធម៌បរិស្ថាន | Environmental justice asks why some communities face greater pollution exposure. |
| 401 | function rule | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: function + rule. Study the complete expression as one field-specific unit. | ច្បាប់មុខងារ | The function rule doubles each input and then adds three. |
| 402 | mathematical relation | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: mathematical + relation. Study the complete expression as one field-specific unit. | ទំនាក់ទំនងគណិតវិទ្យា | The mathematical relation is not a function because one input has two outputs. |
| 403 | function notation | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: function + notation. Study the complete expression as one field-specific unit. | ការសម្គាល់មុខងារ | In function notation, f(4) means the output when the input is four. |
| 404 | independent variable | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: independent + variable. Study the complete expression as one field-specific unit. | អថេរឯករាជ្យ | Time is the independent variable on the horizontal axis. |
| 405 | dependent variable | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: dependent + variable. Study the complete expression as one field-specific unit. | អថេរអាស្រ័យ | Plant height is the dependent variable in the experiment. |
| 406 | input-output table | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: input + output + table. Study the complete expression as one field-specific unit. | តារាងបញ្ចូល-ទិន្នផល | The input-output table reveals that every output is five more than its input. |
| 407 | arithmetic sequence | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: arithmetic + sequence. Study the complete expression as one field-specific unit. | លំដាប់នព្វន្ធ | Three, seven, eleven, and fifteen form an arithmetic sequence. |
| 408 | geometric sequence | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: geometric + sequence. Study the complete expression as one field-specific unit. | លំដាប់ធរណីមាត្រ | Two, six, eighteen, and fifty-four form a geometric sequence. |
| 409 | recursive formula | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: recursive + formula. Study the complete expression as one field-specific unit. | រូបមន្ត recursive | The recursive formula adds four to the preceding term. |
| 410 | explicit formula | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: explicit + formula. Study the complete expression as one field-specific unit. | រូបមន្តច្បាស់លាស់ | The explicit formula gives the fiftieth term without listing the earlier terms. |
| 411 | common difference | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: common + difference. Study the complete expression as one field-specific unit. | ភាពខុសគ្នាទូទៅ | The sequence 5, 8, 11 has a common difference of three. |
| 412 | common ratio | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: common + ratio. Study the complete expression as one field-specific unit. | សមាមាត្ររួម | The sequence 4, 12, 36 has a common ratio of three. |
| 413 | exponential function | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: exponential + function. Study the complete expression as one field-specific unit. | អនុគមន៍អិចស្ប៉ូណង់ស្យែល | The exponential function models a population that doubles each year. |
| 414 | quadratic function | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: quadratic + function. Study the complete expression as one field-specific unit. | មុខងារបួនជ្រុង | The graph of a quadratic function is a parabola. |
| 415 | parabola | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Base-form focus: parabola is the dictionary headword; compare its inflected or derived forms in context. | ប៉ារ៉ាបូល | The ball's idealized path resembles a downward-opening parabola. |
| 416 | parabola vertex | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: parabola + vertex. Study the complete expression as one field-specific unit. | កំពូលប៉ារ៉ាបូឡា | The parabola vertex gives the projectile's greatest height. |
| 417 | axis of symmetry | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: axis + of + symmetry. Study the complete expression as one field-specific unit. | អ័ក្សស៊ីមេទ្រី | The axis of symmetry passes through the vertex of the parabola. |
| 418 | quadratic equation | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: quadratic + equation. Study the complete expression as one field-specific unit. | សមីការការ៉េ | The quadratic equation has two real solutions. |
| 419 | leading coefficient | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: leading + coefficient. Study the complete expression as one field-specific unit. | មេគុណនាំមុខ | A negative leading coefficient makes this parabola open downward. |
| 420 | constant term | noun StudyField: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: constant + term. Study the complete expression as one field-specific unit. | រយៈពេលថេរ | In the expression 3x plus 7, seven is the constant term. |
Vocabulary reading and practice
Page 12 vocabulary review
Review five selected words from page 12.
English reading
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Khmer translation
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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).