Vocabulary and Synonyms

Impeccable means flawless or entirely without fault - the prefix 'im-' means 'not' and 'peccable' comes from 'peccare' (to sin). Faultless is the correct synonym as both describe something completely perfect. Purgative (cleansing), wrong (incorrect), disabled (unable to do something), and raw (unrefined) are all unrelated to the concept of flawlessness.

Imperious means assuming power or authority without justification; arrogant and domineering. Commanding is the correct synonym as both convey the sense of exercising authority and expecting obedience. Odd (strange), obedient (compliant - the opposite), absolve (to forgive), and perilous (dangerous) don't capture the authoritarian attitude.

Implausible means not seeming reasonable or probable; unlikely to be true. Unlikely is the correct synonym as both convey low probability. Likely (A), possible (B), conceivable (D), and comprehensible (E) are all antonyms or unrelated - they suggest something could happen, whereas implausible suggests it probably won't.

Imperturbable means unable to be upset or excited; calm and composed. Serene is the correct synonym as both describe a peaceful, untroubled state. Confused, disturbed, and vulnerable are all antonyms that suggest being affected by emotions. Passive is unrelated to calmness.

Impending means about to happen; forthcoming or imminent. Imminent is the correct synonym as both describe something about to occur very soon. Impossible and unlikely suggest something won't happen, while dominating and dogmatic refer to exercising authority.

Impair means to weaken, damage, or make worse. Injure is the correct synonym as both involve causing harm or damage. Capable, special, and sociable are all positive attributes unrelated to harm. Heal is an antonym - it means to cure or repair, which is the opposite of impair.

Impolitic means lacking good judgment or wisdom, often in a way that is politically or socially disadvantageous. Unwise is the direct synonym. Prudent is actually an antonym, while political only relates to government without capturing the 'unwise' meaning.

Importune means to ask or request persistently or urgently, sometimes to the point of annoyance. Request is the closest match among the options. Command, demand, and order imply authority that importune lacks.

Impugn means to challenge, criticize, or call into question someone's actions, character, or motives. Criticize is the correct match. Promote, praise, and laud are all antonyms. Recommend suggests approval rather than questioning.

Inadvertence means the quality of being unintentional or accidental, lacking attention or care. Unintentional is the direct synonym. Planned and intentional are antonyms. Adventurous is unrelated to the concept of accidental oversight.

Incarcerate means to imprison or confine someone in a prison or jail. Imprison is the exact synonym. Release and free are direct antonyms. Impregnate refers to fertilization, and decapitate means to behead, both unrelated.

Immune means protected or secure from disease, infection, or influence. Secure is the correct synonym as it captures the sense of protection. Imprison, impure, and impute are unrelated meanings. The prefix 'im-' here means 'not' susceptible to.

Incandescent means emitting light, brilliant, or extremely bright. Brilliant is the perfect synonym. Blighted, dull, and dark are all antonyms describing the opposite. Cannibalistic is completely unrelated to light or brightness.