Definition for Underhanded:

• Underhand; clandestine.

Synonyms for Underhanded:

• adj.

  •deceitful (adjective)
  • covert,
  • crooked,
  • fraudulent,
  • sneaky,
  • shady,
  • shorthanded,
  • unfair,
  • dirty,
  • surreptitious,
  • clandestine,
  • unethical,
  • cunning.
  •dishonest (adjective)
  • double-faced,
  • deceptive,
  • insincere,
  • untrustworthy,
  • corrupt,
  • dishonorable,
  • treacherous,
  • traitorous,
  • hypocritical,
  • Prevaricating,
  • cheating,
  • Deceiving,
  • felonious,
  • immoral,
  • turncoat,
  • crafty.

• n.

  •
  • shadowy,
  • classified,
  • confidential,
  • mysterious.

Antonyms for Underhanded:

• adj.

  • deceitful
    frank, trustworthy, good, fair, open, ethical, principled, public, honest, scrupulous, moral, truthful, aboveboard.
  • Other antonyms:
    unconcealed, decent, straightforward, just, overt, plain, obvious, forthright, clear, acknowledged, avowed, scrupulous, aboveboard, manifest, unclassified, conscientious, square, unrestricted, honorable, upright, ethical, undisguised, patent, evident.