from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Extremely foolish or silly.
- adj. Crazy; insane.
- n. A foolish or crazy person.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. insane
- adj. very silly, absurd
- n. An insane or very foolish person
from the GNU version of the Collaborative International Dictionary of English
- adj. Crazy; insane; lunatic; mentally unsound.
- adj. Very foolish; very impractical.
- n. someone mentally deranged and possibly dangerous.
from The Century Dictionary and Cyclopedia
- n. See luny.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. someone deranged and possibly dangerous
- adj. informal or slang terms for mentally irregular
Shortening and alteration of lunatic, or from loon2.(American Heritage® Dictionary of the English Language, Fourth Edition)
Shortened from lunatic (Wiktionary)