careless vs offhand

careless and offhand both are adjectives.

Word	Noun	Adjective	Verb	Adverb
careless	No	Yes	No	No
offhand	No	Yes	No	Yes

careless (adjective)	offhand (adjective)
marked by lack of attention or consideration or forethought or thoroughness; not careful	casually thoughtless or inconsiderate
effortless and unstudied	with little or no preparation or forethought
(usually followed by `of') without due thought or consideration

careless (adverb)	offhand (adverb)
	in a casually inconsiderate manner
	without previous thought or preparation