ANT: Mature, later, manly, womanly, elderly, aged, senile, anile, superannuated, adult.

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KEY: Juxtaposition.

SYN: Proximity, contiguity, contact, [See CONTACT].

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KEY: Keen.

SYN: Eager, vehement, sharp, piercing, penetrating, acute, cutting, biting, severe, sarcastic, satirical, ardent, prompt, shrewd.

ANT: Indifferent, languid, blunt, dull, blind.

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KEY: Keep.