frenetic (adj.) Look up frenetic at Dictionary.com
late 14c., from Old French frenetike, from Latin phreneticus "delirious," alteration of Greek phrenitikos, from phrenitis "frenzy," literally "inflammation of the brain," from phren "mind, reason" (from PIE *gwhren- "to think") + -itis. The classical ph- was restored mid-16c. Related: Frenetically.