from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Seeming to be coolly unconcerned or indifferent. See Synonyms at cool.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Casually calm and relaxed.
- adj. Indifferent; unconcerned; behaving as if detached.
from the GNU version of the Collaborative International Dictionary of English
- adj. Indifferent; careless; cool.
from The Century Dictionary and Cyclopedia
- Indifferent; unconcerned; careless; cool: as, he replied with a nonchalant air.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. marked by blithe unconcern
French, from Old French, present participle of nonchaloir, to be unconcerned : non-, non- + chaloir, to cause concern to (from Latin calēre, to be warm, heat up).(American Heritage® Dictionary of the English Language, Fourth Edition)
From French nonchalant, from Old French nonchaloir ("to not be concerned"), from non- ("not") + chaloir ("to have concern for"), from Latin non 'not' + calere 'to be warm' (Wiktionary)