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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Words 456–490 of 800
#	Word	Details	Meaning	Sample sentence
456	residual	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Base-form focus: residual is the dictionary headword; compare its inflected or derived forms in context.	the difference between an observed value and the value predicted by a model	A positive residual means the observation lies above the prediction.
457	residual plot	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: residual + plot. Study the complete expression as one field-specific unit.	a graph of residuals used to evaluate how well a model fits data	A curved pattern in the residual plot suggests that a linear model is unsuitable.
458	interpolation	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Suffix focus: -ation commonly forms a noun naming an action, process, or result.	estimation of a value within the range of known data	Interpolation estimates the temperature between two recorded times.
459	two-column proof	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: two + column + proof. Study the complete expression as one field-specific unit.	a geometric proof listing statements beside the reasons that justify them	The two-column proof pairs each angle claim with a definition or theorem.
460	paragraph proof	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: paragraph + proof. Study the complete expression as one field-specific unit.	a geometric proof written as connected explanatory sentences	The paragraph proof explains why corresponding parts of the triangles are congruent.
461	logical statement	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: logical + statement. Study the complete expression as one field-specific unit.	a declarative sentence that has a truth value	“Seven is prime” is a true logical statement.
462	conditional statement	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: conditional + statement. Study the complete expression as one field-specific unit.	a logical statement in if-then form	The conditional statement says that if an angle is right, then it measures ninety degrees.
463	converse	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Base-form focus: converse is the dictionary headword; compare its inflected or derived forms in context.	the statement formed by switching the hypothesis and conclusion of a conditional	The converse of “if it is a square, then it is a rectangle” is not always true.
464	inverse	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Base-form focus: inverse is the dictionary headword; compare its inflected or derived forms in context.	the statement formed by negating both the hypothesis and conclusion of a conditional	The inverse does not necessarily share the original statement's truth value.
465	contrapositive	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Base-form focus: contrapositive is the dictionary headword; compare its inflected or derived forms in context.	the statement formed by switching and negating a conditional's hypothesis and conclusion	A conditional and its contrapositive are logically equivalent.
466	biconditional	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Base-form focus: biconditional is the dictionary headword; compare its inflected or derived forms in context.	a statement asserting that two conditions are both necessary and sufficient	A biconditional can be written with the phrase “if and only if.”
467	truth value	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: truth + value. Study the complete expression as one field-specific unit.	the classification of a logical statement as true or false	A counterexample proves that the universal statement has a false truth value.
468	axiomatic system	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: axiomatic + system. Study the complete expression as one field-specific unit.	a logical framework built from undefined terms, definitions, axioms, and derived theorems	Euclidean geometry is an axiomatic system.
469	congruence theorem	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: congruence + theorem. Study the complete expression as one field-specific unit.	a proven rule for establishing that figures have the same size and shape	The side-angle-side congruence theorem proves the triangles match.
470	similarity theorem	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: similarity + theorem. Study the complete expression as one field-specific unit.	a proven rule for establishing that figures have equal corresponding angles and proportional sides	The angle-angle similarity theorem applies to the two triangles.
471	triangle congruence	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: triangle + congruence. Study the complete expression as one field-specific unit.	the condition in which two triangles match exactly in size and shape	Three corresponding side lengths can establish triangle congruence.
472	angle relationship	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: angle + relationship. Study the complete expression as one field-specific unit.	a defined connection between angles created by lines or shapes	The diagram shows an angle relationship between alternate interior angles.
473	parallel line	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: parallel + line. Study the complete expression as one field-specific unit.	one of two coplanar lines that never intersect	Each rail is a parallel line relative to the other.
474	algorithmic procedure	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: algorithmic + procedure. Study the complete expression as one field-specific unit.	a finite ordered set of steps for solving a problem or completing a task	The sorting program follows an algorithmic procedure.
475	pseudocode	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Base-form focus: pseudocode is the dictionary headword; compare its inflected or derived forms in context.	a language-independent description of an algorithm written in structured ordinary language	The pseudocode states when the loop should stop.
476	flowchart	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Base-form focus: flowchart is the dictionary headword; compare its inflected or derived forms in context.	a diagram using connected shapes to show steps and decisions in a process	The flowchart sends a failed login back to the password step.
477	variable declaration	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: variable + declaration. Study the complete expression as one field-specific unit.	a programming statement that creates a variable and may specify its type or initial value	The variable declaration reserves storage for the score.
478	data type	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: data + type. Study the complete expression as one field-specific unit.	a classification that determines what values data can hold and what operations are valid	A Boolean data type stores true or false.
479	Boolean	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Capitalization focus: Boolean is conventionally capitalized because the term comes from the name George Boole.	a logical data value restricted to true or false	The comparison returns a Boolean.
480	conditional branch	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: conditional + branch. Study the complete expression as one field-specific unit.	a section of code selected according to whether a condition is true	The conditional branch displays an error when the password is incorrect.
481	loop	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Base-form focus: loop is the dictionary headword; compare its inflected or derived forms in context.	a programming structure that repeats instructions while a condition holds or for a set number of times	The loop processes every item in the list.
482	loop iteration	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: loop + iteration. Study the complete expression as one field-specific unit.	one complete execution of a loop's repeated instructions	During each loop iteration, the index increases by one.
483	debugging	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Base-form focus: debugging is the dictionary headword; compare its inflected or derived forms in context.	the process of finding, understanding, and correcting defects in software	Debugging revealed that the program compared text instead of numbers.
484	compiler	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Base-form focus: compiler is the dictionary headword; compare its inflected or derived forms in context.	software that translates a complete program into another form before execution	The compiler reported a missing bracket.
485	interpreter	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Base-form focus: interpreter is the dictionary headword; compare its inflected or derived forms in context.	software that reads and executes program instructions directly	The interpreter stopped when it encountered an undefined name.
486	source code	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: source + code. Study the complete expression as one field-specific unit.	human-readable instructions written in a programming language	The developer reviewed the source code before releasing the update.
487	object code	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: object + code. Study the complete expression as one field-specific unit.	low-level instructions produced by translating source code for a computer	The compiler converted the program into object code.
488	network security	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: network + security. Study the complete expression as one field-specific unit.	protection of connected systems and data from unauthorized access or disruption	Network security includes firewalls, monitoring, and controlled permissions.
489	data encryption	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Term structure: data + encryption. Study the complete expression as one field-specific unit.	the conversion of readable data into coded form requiring a key to restore	Data encryption protects the message while it travels across the network.
490	decryption	noun Study Field: Grade 9 mathematics, computing, and data-literacy term Word study: Suffix focus: -tion commonly forms a noun naming an action, process, or result.	the conversion of encrypted information back into readable form	Authorized decryption requires the correct key.

Vocabulary reading and practice

Page 14 vocabulary review

Review five selected words from page 14.

Vocabulary quiz

Complete 5 review questions for this page.

1. The ___ displays an error when the password is incorrect.

Answer: conditional branch

2. Euclidean geometry is an ___.

Answer: axiomatic system

3. The ___ processes every item in the list.

Answer: loop

4. A positive ___ means the observation lies above the prediction.

Answer: residual

5. The side-angle-side ___ proves the triangles match.

Answer: congruence theorem

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9th Grade Vocabulary Words

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