Origin: 1325–75; late Middle English testi, alteration of Middle French testu headstrong; replacing Middle English testif < Middle French. See test2, -ive
Related forms
tes·ti·ly, adverb
tes·ti·ness, noun
Synonyms tetchy, edgy, snappish, cross, irascible. See irritable.
1510, "impetuous, rash," from M.E. testif "headstrong" (late 14c.), from Anglo-Fr. testif, from O.Fr. testu "stubborn," lit. "heady," from teste "head," from L.L. testa "skull," in L. "pot, shell" (see tester (2)). Meaning "easily irritated" is first recorded 1526.