slaughter (n.) Look up slaughter at Dictionary.com
c.1300, "killing of a cattle or sheep for food, killing of a person," from a Scandinavian *slahtr, akin to Old Norse slatr "a butchering, butcher meat," slatra "to slaughter," slattr "a mowing" from Proto-Germanic *slukhtis, related to Old Norse sla "to strike" (see slay (v.)) + formative suffix (as in laugh/laughter). Meaning "killing of a large number of persons in battle" is attested from mid-14c. Old English had slieht "stroke, slaughter, murder, death; animals for slaughter;" as in sliehtswyn "pig for killing."
slaughter (v.) Look up slaughter at Dictionary.com
1530s, "butcher an animal for market," from slaughter (n.). Meaning "slay wantonly, ruthlessly, or in great numbers" is from 1580s. Related: Slaughtered; slaughtering.