Offhand can be used as an adverb, where it means unprepared or brusquely; and as an adjective, where it means casual.
President Clinton made an offhand confession on Tuesday night that he had raised taxes “too much” in his first budget in 1993, and the remark drew mockery from Congressional Republicans today. (NY Times)
While adults will approve of the scenery, offhand humor and mild attempts at cultural sensitivity, children will like the sword fights and Crusoe’s ingenuity. (USA Today)