Save Gender Feminine Usage Anglo-Saxon Other Forms FormsSæthryth, Sæthrith, Sedrido, Sethrida, Sethryda, Saethrid, Sæthryd, Sæthryda, Saeðryð, Sethrid, Seðrið, Seðryð, Sæðryð, Sæðryþ, Sæþryþe Meaning & History Derived from Old English sæ "sea" and þryþ "strength, power, force".