slaughter: [13] Slaughter was borrowed from Old Norse *slahtr, which went back to the same prehistoric Germanic base (*slakh- ‘strike’) that produced English slay. Old English appears to have had its own version of the word, *slæht, which survived into the 17th century as slaught. This forms the second syllable of onslaught [17], where it replaced the -slag in the borrowing from Middle Dutch aenslag (literally ‘onstriking’). => onslaught, slay[slaughter etymology, slaughter origin, 英语词源]