mid-15c., "dead, departed from life," past-participle adjective from decease (v.). As a verbal noun meaning "dead person, those who are dead," from early 17c.
"death of bodily tissue," 1660s, from Latinized form of Greek nekrosis "a becoming dead, state of death," from nekroun "make dead," from nekros "dead body" (from PIE root *nek- (1) "death"). Related: Necrotic.
also distil, late 14c., distillen, "to let fall in drops" (transitive); early 15c., "to drop, trickle, drip, fall in drops" (intransitive), from Old French distiller (14c.), from Latin distillare "trickle down in minute drops," from dis- "apart" (see dis-) + stillare "to drip, drop," from stilla "drop," which is of uncertain origin, perhaps from a PIE root *sti-. De Vaan compares Greek stile "drop;" Lithuanian styri "to become stiff," Old Norse stira "to be rigid, stiff," but has doubts about all of them. From late 14c. as "obtain or extract by distillation;" from c. 1400 as "subject to distillation." Related: Distilled; distilling.
"urn or vase for the bones of the dead;" also "place where bones of the dead are deposited," 1650s, from Late Latin ossuarium "charnel house, receptacle for bones of the dead," from neuter of Latin ossuarius "of bones," from Latin os (plural ossua) "bone" (from PIE root *ost- "bone") on model of mortuarium.