I. ˌən-dər-ˈhan-dəd adverb
Date: circa 1822
: underhand
II. adjective
Date: 1853
: marked by secrecy, chicanery, and deception : not honest and aboveboard : sly
an underhanded attempt to gain power
Synonyms: see secret
• un·der·hand·ed·ly adverb
• un·der·hand·ed·ness noun