Synonyms

Cataclysm means a sudden, violent event that brings great change or disaster - like earthquakes or floods. 'Disaster' captures this meaning of large-scale destruction. 'Extinction' is too specific (species ending), while 'boon' and 'adventure' are opposites.

Cathartic means providing psychological relief through open expression (emotional) or purging/cleansing (physical/medical). 'Purgative' directly relates to the medical meaning - something that cleanses or purges. 'Alleviate' is related but different (reduces severity).

Catholic (lower-case c) means universal, comprehensive, or broad-minded - covering all things or people. This derives from the Greek 'katholikos'. 'Universal' is the direct synonym. The religious term 'Catholic' comes from this meaning of universal church.

Castigate means to criticize or reprimand someone severely, often in a formal way. 'Chastise' is the closest synonym - meaning to punish, scold, or criticize harshly. 'Praise' and 'applaud' are antonyms. 'Free' and 'rejuvenate' are unrelated.

Cavil means to raise petty or trivial objections, to find fault with unimportant details. 'Raise trivial objections' is the precise definition. 'Surrender' and 'suppress' are actions, not arguments. 'Prejudiced' and 'inexperienced' describe people, not the act of objecting.

To cede to someone or something refers to yield or formally surrender or relinquish. 

Chagrin means a feeling of embarrassment, disappointment, or distress - usually from failure or humiliation. 'Embarrassment' is the closest match among options. 'Agony' and 'peril' are too strong. 'Esteem' is opposite. 'Displeasure' is milder and different.

Chicanery means the use of trickery, clever but dishonest practices, or deception to achieve a goal. 'Deception' captures this core meaning. 'Genuine' and 'innocent' are antonyms. 'Futile' and 'malleable' are unrelated concepts.

Cherubic means resembling a cherub - angelic, innocent, sweet, or having a chubby, innocent-looking face (especially of children). 'Angelic' is the direct synonym. 'Ugly' and 'malevolent' are opposites. 'Cannibalistic' is completely unrelated. 'Wonderful' is too vague.

Citadel means a fortress or stronghold overlooking a city, used for defense. 'Fortress' is the direct synonym. 'Valley' and 'trench' are geographic depressions (opposite). 'Temple' is religious architecture. 'Heights' is vague - a citadel is ON heights but not the heights themselves.

Choleric means hot-tempered, easily angered, or irritable - from the four humors theory where yellow bile caused anger. 'Short-tempered' is the direct synonym. 'Patient' is the opposite. 'Ascetic' relates to self-denial. 'Sophisticated' and 'courteous' describe refined behavior.

'Censorious' means severally critical or faultfinding.

Cleave means to split or separate something, typically by force. Option D 'split' is the correct synonym. Other options like 'join,' 'united,' 'cement,' and 'associate' are antonyms or unrelated, making them easy to eliminate.

Cogent refers to an argument that is convincing, compelling, and logically sound. Option D 'convincing' is the correct synonym. Options A, B, and C are antonyms, while E 'reasonable' is close but less precise than the primary meaning.

Coddle means to treat with excessive care or indulgence, like pampering someone. Option A 'treat tenderly' correctly captures this meaning. The other options (abuse, mismanage, use force, compel) are opposite behaviors.