Origin and history of *plak-

"sudden fit of paralysis and dizziness," late 14c., from Old French apoplexie or directly from Late Latin apoplexia, from Greek apoplexia, from apoplektos "disabled by a stroke, struck dumb," verbal adjective from apoplēssein "to strike down and incapacitate," from apo "off" (see apo-), in this case perhaps an intensive prefix, + plēssein "to hit" (from PIE root *plak- (2) "to strike;" source also of plague, which also has a root sense of "stricken"). The Latin translation, sideratio, means "disease caused by a constellation."

"sudden nervous shock and paralysis, the state of an animal when it is feigning death," 1880, Latinized and Anglicized from German Kataplexie (1878), from Greek kataplexis "stupefaction, amazement, consternation," from kataplēssein "to strike down" (with fear, etc.), from kata "down" (see cata-) + plēssein "to strike, hit" (from PIE root *plak- (2) "to strike"). The German word was coined by William Thierry Preyer (1841-1897), English-born German physiologist, in "Die Kataplexie und der thierische Hypnotismus" (Jena). Related: Cataplectic.