Underhanded meaning : To toss or lob with an underhand movement. To trick, deceive or gull. To excavate downward in successive steps or horizontal slices while positioned above on unbroken ore. Devious people, collectively. Done by moving the hand (and arm) from below. Sly, dishonest, corrupt, cheating. Insincere; sarcastic. Secret; surreptitious. Understaffed. In an underhanded manner.