offhanded

with little or no preparation or forethought; "his ad-lib comments showed poor judgment"; "an extemporaneous piano recital"; "an extemporary lecture"; "an extempore skit"; "an impromptu speech"; "offhand excuses"; "trying to sound offhanded and reassuring"; "an off-the-cuff toast"; "a few unrehearsed comments"

casually thoughtless or inconsiderate; "an offhand manner"; "she treated most men with offhand contempt"

without previous thought or preparation; "couldn't give the figures offhand"; "we decided offhand to go to Canada"; "she had made these remarks offhandedly"

in a casually inconsiderate manner; "replied offhand, his mind a million miles away"; "she threw him over offhandedly without even a Dear-John letter"