From Ottoman Turkish سنجاق (sancak, “flag; subdivision of a vilayet”), from Proto-Turkic *sančgak (“lance, streamer attached to a spear”). Cognate with the verb sançmak (“to stab”), also found as Azerbaijani sancmaq (“to stab”), Bashkir сәнсеү (sənsew, “to stab”), Kazakh шаншу (şanşu, “to stab”), Turkmen sançmak, etc. Related to sancı (“pain, ache”).