aft (adv.)youdaoicibaDictYouDict[aft 词源字典]
Old English æftan "from behind, behind, farthest back," from superlative of Old English æf, af, of "away, away from, off" (see of). The Germanic superlative suffix *-ta corresponds to PIE *-to (compare Greek protos "first," superlative of pro "before"). Now purely nautical.[aft etymology, aft origin, 英语词源]