loony

a.	1.	Crazy; insane; lunatic; mentally unsound.
	2.	Very foolish; very impractical; as, loony ideas.
n.	1.	someone mentally deranged and possibly dangerous.

Noun	1.	loony - someone deranged and possibly dangerous Synonyms: crazy, looney, weirdo
Adj.	1.	loony - informal or slang terms for mentally irregular; "it used to drive my husband balmy" Synonyms: bats, batty, bonkers, buggy, crackers, daft, dotty, haywire, kookie, kooky, loco, loopy, nuts, around the bend, balmy, round the bend, wacky, whacky, barmy, nutty, fruity, cracked

absurd, apish, asinine, balmy, bananas, barmy, bats, batty, beany, bedlamite, befooled, beguiled, besotted, bonkers, brainless, buffoonish, buggy, bughouse, bugs, cockeyed, crackers, crazy, credulous, cuckoo, daffy, daft, dazed, dement, dippy, dizzy, doting, dotty, dumb, fatuitous, fatuous, flaky, flipped, fond, fool, foolheaded, foolish, freaked-out, fruitcakey, fruity, fuddled, futile, gaga, goofy, gulled, harebrained, haywire, idiotic, imbecile, inane, inept, infatuated, insane, just plain nuts, kooky, loon, loopy, mad, madman, maniac, maudlin, moronic, non compos, nut, nuts, nutty, off the hinges, off the track, off the wall, potty, preposterous, round the bend, sappy, screwball, screwballs, screwy, senseless, sentimental, silly, slaphappy, stupid, thoughtless, wacky, wet, witless