Entry 2 senses · 2 variants Webster, 1913 Phrensy · Phren·sy · IPA n. v. t. 01 n. Violent and irrational excitement; delirium. See Frenzy. 1. Violent and irrational excitement; delirium. See Frenzy. See: Frenzy 02 v. t. To render frantic. 1. To render frantic.