The definition of underhanded is sneaky or deceitful.
An example of something underhanded is a plot to ruin someone's date.
- not open or straightforward; secret, sly, deceitful, etc.
- Acting or done in a deceptive, secret, or sly manner; dishonest and sneaky. See Synonyms at secret.
- Underhand: an underhanded toss.
- In a sly and secret way.
- With an underhand movement.
(comparative more underhanded, superlative most underhanded)
- Nouns to which "underhanded" is often applied: tactic, way, dealing, method, trick, manner, thing, deal, scheme, practice.