underhand vs crooked

underhand and crooked both are adjectives.

Word	Noun	Adjective	Verb	Adverb
underhand	No	Yes	No	Yes
crooked	No	Yes	No	No

underhand (adjective)	crooked (adjective)
with hand brought forward and up from below shoulder level	having or marked by bends or angles; not straight or aligned
marked by deception	not straight; dishonest or immoral or evasive
	irregular in shape or outline
	having the back and shoulders rounded; not erect

underhand (adverb)	crooked (adverb)
with the hand swung below shoulder level
slyly and secretly