noun

1. the killing of an animal or animals for food; butchering
2. the killing of a human being, esp. in a brutal manner
3. the killing of people in large numbers, as in battle
4. Informal a complete defeat or victory

Etymology: ME slahter < ON slātr, lit., slain flesh, contr. < slattr, akin to OE sleaht, slaughter, death: for IE base see slay

transitive verb

1. to kill (an animal or animals) for food; butcher
2. to kill (people), esp. brutally or in large numbers
3. Informal to conquer or defeat completely