SYN: Expand, lighten, attenuate, sublimate.
ANT: Solidify, condense, thicken.
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KEY: Rascal.
SYN: Rogue, scoundrel, vagabond, scamp, villain, knave.
ANT: Gentleman.
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KEY: Rash.
SYN: Headstrong, audacious, hasty, precipitate, reckless, foolhardy, careless, adventurous, thoughtless, indiscreet, venturesome, overventuresome, incautious, unwary, heedless.
ANT: Wary, cautious, calculating, discreet, unventuresome, dubitating, hesitating, reluctant, timid.