"burn to ashes" (transitive), 1550s, from Medieval Latin incineratus, past participle of incinerare "reduce to ashes," from in- "into" (from PIE root *en "in") + a verb from Latin cinis (genitive cineris) "ashes," from PIE root *keni- "dust, ashes" (source also of Greek konis "dust"). Middle English had the word, from Latin, but only as a past-participle adjective meaning "reduced to ashes" (early 15c.). Related: Incinerated; incinerating.