n. Function: noun
one given to extremely eccentric or lunatic ideas or actions FF1C; a crackpot who wrote threatening letters to public figures FF1E;
Synonyms: crackbrain, crank, cuckoo, ding-a-ling, harebrain, kook, lunatic, nut, screwball
Related Words: case, character, ||dingbat, eccentric, oddball, oddity, ||wack; loon, loony, madman, maniac