late 13c., cors "body," from Old French cors "body; person; corpse; life" (9c.), from Latin corpus "body" (from PIE root *kwrep- "body, form, appearance"). The order of appearance of senses in English is "dead body" (13c.), "live body" (14c.); it also meant "body of citizens" (15c.), "band of knights" (mid-15c.), paralleling the sense evolution in French that yielded the doublet corps.
French restored the Latin -p- in 14c., and English followed 15c., but the pronunciation remained "corse" at first (and perhaps remains so with some speakers) and corse persisted as a parallel spelling. After the -p- began to be sounded (16c. in English), corse became archaic or poetic only. The terminal -e was rare before 19c.
Corpse-candle "candle used at ceremonial watchings of a corpse before burial," is attested from 1690s.