from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Slang Trifling; nearly valueless.
- adj. Slang Ludicrous; nonsensical: gave me a cockamamie reason for not going.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. foolish, silly
- adj. trifling
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. ludicrous, foolish
Probably alteration of decalcomania.(American Heritage® Dictionary of the English Language, Fourth Edition)
From French; derived from décalcomanie, a word used to describing the popular use of children's rub-on tattoos or other transfer decals. Sometimes erroneously claimed to derive from Yiddish (Wiktionary)