Definitions
1.nounThe lower of two hands, the hand under the work."Your underhand should be entirely under the quilt."
2.verbTo toss or lob with an underhand movement.
3.verbTo trick, deceive or gull.
4.verbTo excavate downward in successive steps or horizontal slices while positioned above on unbroken ore.
5.adjectiveSecret; clandestine
6.adjective(by extension) dishonest and sneaky; done in a secret or sly manner
7.adjective(in various ball games, of a ball) thrown (etc.) with the hand brought forward and up from below
8.adverbWith an underhand movement
9.adverbIn a sly, sneaky or secret manner