Based on, having, or manifesting principles
strongly adhering to, or heedful of, guiding beliefs or moral rules
Done by moving the hand (and arm) from below.
Sly, dishonest, corrupt, cheating.
Insincere; sarcastic.
An underhanded compliment is actually criticism.
Secret; surreptitious.
His underhanded trick backfired and he was disqualified.
Understaffed.
Devious people, collectively.
In an underhanded manner.