Dishonest or illegal; corrupt.
Not straight; having one or more bends or angles.
Set at an angle; not vertical or square.
Sly, dishonest, corrupt, cheating.
Done by moving the hand (and arm) from below.
Insincere; sarcastic.
An underhanded compliment is actually criticism.
Secret; surreptitious.
His underhanded trick backfired and he was disqualified.
Understaffed.
In an underhanded manner.
Devious people, collectively.