An Etymological Dictionary of the German Language/Annotated/Sitte

by Friedrich Kluge

Sitte, feminine, ‘custom, manner, good-breeding,’ from the equivalent Middle High German site, masculine (rarely feminine), Old High German situ, masculine; a common Teutonic word; compare the equivalent Gothic sidus, Old Icelandic siðr, Anglo-Saxon sidu (wanting in English), Dutch zede, Old Saxon sidu. It is very probably allied primitively to Greek ἔθω, genitive ἔθεος (Aryan primary form sédhos), ‘custom,’ but its connection with Greek ἔ-μος, ‘true,’ is less likely.