DictionaryunderhandSecret or dishonest
adjective

underhand

un-der-HAND/ˌʌndərˈhænd/

Done secretly or dishonestly.

The card player uses an underhand trick, hiding an extra card in his sleeve.

A card player secretly slips a concealed playing card from his sleeve beneath the table while his opponent studies her hand above it.
Etymology

Under hand originally meant being in someone's control or power. The later secretive sense may picture a hand turned over to conceal what it holds, an image fitting actions hidden from scrutiny.

In context

Vivid Audio Library411:23
It was one thing to watch Miss Norton by legitimate methods, and quite another to try underhand ways. She wondered whether the service of her country really demanded such a sacrifice of honor.
A Patriotic School Girl by Angela Brazil | Full Classic British School Story Audiobook

More examples

  • She objected to the underhand arrangement made without the team’s knowledge.
  • He discovered an underhand attempt to alter the results.
  • The detective exposed the underhand deal.

Forms

underhand · more underhand · most underhand

underhanded adjective — dishonest or unfair

Similar words

dishonest
Dishonest broadly involves deception; underhand stresses concealed, unfair methods.
sneaky
Sneaky emphasizes avoiding notice; underhand also implies unfairness.