Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun loony

1 sense of loony

Sense 1
crazy, loony, looney, nutcase, weirdo -- (someone deranged and possibly dangerous)
       => lunatic, madman, maniac -- (an insane person)

Antonyms of adj loony

1 sense of loony

Sense 1
balmy, barmy, bats, batty, bonkers, buggy, cracked, crackers, daft, dotty, fruity, haywire, kooky, kookie, loco, loony, loopy, nuts, nutty, round the bend, around the bend, wacky, whacky -- (informal or slang terms for mentally irregular; "it used to drive my husband balmy")

INDIRECT (VIA insane) -> sane -- (mentally healthy; free from mental disorder; "appears to be completely sane")

Similarity of adj loony

1 sense of loony

Sense 1
balmy, barmy, bats, batty, bonkers, buggy, cracked, crackers, daft, dotty, fruity, haywire, kooky, kookie, loco, loony, loopy, nuts, nutty, round the bend, around the bend, wacky, whacky -- (informal or slang terms for mentally irregular; "it used to drive my husband balmy")
       => insane (vs. sane) -- (afflicted with or characteristic of mental derangement; "was declared insane"; "insane laughter")