"sudden attack, convulsion," early 15c., from Middle French paroxysme (16c.), earlier paroxime (13c.), from Medieval Latin paroxysmus "irritation, fit of a disease," from Greek paroxysmos "irritation, exasperation," from paroxynein "to irritate, goad, provoke," from para- "beyond" (see para- (1)) + oxynein "sharpen, goad," from oxys "sharp, pointed" (see acrid). Non-medical sense first attested c.1600. Related: Paroxysmal.
paroxysm par·ox·ysm (pār'ək-sĭz'əm)
A sharp spasm or fit; a convulsion.
A sudden onset of a symptom or disease, especially one with recurrent manifestations, such as the chills and fever of malaria.