offhand

from The American Heritage® Dictionary of the English Language, 4th Edition

• adv. Without preparation or forethought; extemporaneously.
• adj. Performed or expressed without preparation or forethought. See Synonyms at extemporaneous.

from Wiktionary, Creative Commons Attribution/Share-Alike License

• adj. without planning or thinking ahead
• adj. careless; without sufficient thought or consideration
• adj. curt, abrupt, unfriendly
• adv. right away, immediately, without thinking about it
• adv. in an offhand manner

from the GNU version of the Collaborative International Dictionary of English

• n. forthwith; without delay, hesitation, or difficulty; promptly.
• prep. See Offhand.
• adj. Instant; unprepared; ready; extemporaneous; unrehearsed

from The Century Dictionary and Cyclopedia

• At once; without deliberation or premeditation; without previous preparation or practice.
• From the hand; without the support of a rest.
• Without study or premeditation; impromptu: as, an offhand remark; an offhand speech.
• Free and easy; unstudied or unconventional: as, an offhand manner.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adv. without preparation
• adv. in a casually inconsiderate manner
• adj. with little or no preparation or forethought
• adj. casually thoughtless or inconsiderate
• adv. without previous thought or preparation