From Middle English sainen, seinen, senen, sinen, signen, from Old English sēnian, seġnian, from Proto-Germanic *segnōną (“to mark with a cross, bless”), from Latin signō, from signum. Cognate with Dutch zegenen (“to bless”), German segnen (“to bless”), Irish séan (“sign, omen”) and Scottish Gaelic seun (“a charm”).