LOONY /ˈluːni/ ► audio Scrabble 8 Words With Friends 9 Definition adjective informal or slang terms for mentally irregular. — synonyms: balmy, barmy, bats, batty, bonkers, buggy, cracked, crackers noun someone deranged and possibly dangerous. — synonyms: crazy, looney, nutcase, weirdo See all 12 words you can make from LOONY → 5-letter words Words starting with L Words ending with Y ← Unscramble different letters