frenzy (n.)
mid-14c., "delirium, insanity," from Old French frenesie "frenzy, madness" (13c.), from Medieval Latin phrenesia, from phrenesis, back-formation from Latin phreneticus "delirious" (see frenetic). Meaning "excited state of mind" is from c. 1400.
frenzy (v.)
1795, from frenzy (n.). Related: Frenzied; frenzying.