From Middle Englishslaught, slagt, slaȝt, from Old Englishslæht, sleaht, sleht, slieht(“a stroke, a striking, a flash of lightning, slaughter, murder, death by violence, the deadly stroke of disease, battle, what is to be killed, animals for slaughter”), from Proto-Germanic*slahtō, *slahtiz(“beating, hitting, killing, murder”), from Proto-Indo-European*slak-(“to beat, pound”). Cognate with Dutchslacht(“slaughter”), GermanSchlacht(“killing, battle”), Swedishslakt(“slaughter”), Icelandicslátta(“slaughter”). Related to slay.