Tomfool \Tom"fool`\ (t[o^]m"f[=oo]l`), n. [Tom (see Tomboy) + fool.]

A great fool; a trifler. [1913 Webster]

Source: The Collaborative International Dictionary of English v.0.48
 

34 Moby Thesaurus words for "tomfool": absurd, ass, balmy, born fool, buffoon, clown, crazy, donkey, doodle, egregious ass, fantastic, figure of fun, fool, harebrained, idiot, ignoramus, imbecile, insane, jackass, jerk, loony, lunatic, milksop, mooncalf, nincompoop, ninny, perfect fool, preposterous, schmuck, silly, softhead, sop, stupid ass, zany

Source: Moby Thesaurus II by Grady Ward, 1.0
 

tomfool

Source: WordNet (r) 2.0
 

Tomfool \Tom"fool`\, n. [Tom (see Tomboy) + fool.]

A great fool; a trifler.

Source: Webster's Revised Unabridged Dictionary (1913)