sgian

a knife, Irish sgian, Early Irish scían, Welsh ysgíen slicer, scimitar, ysgi, citting off Breton skeja, cut: *scêenâ, vb. skêô, cut; Sanskrit châ, cut off, Greek $$Gsházw, cut, $$gsháw; Indo-European root skjê, skha, split, cut. Lindsay refers Gadelic to *scênâ, allied to Latin scêna, a priest's knife, whose side-form is sacena, from seco, cut, English section, saw. Others have compared Latin scio, know, Greek $$Gkeíw, cut.