fem. proper name, 13c., from earlier Aldreda (11c.), contracted from Etheldreda, a Latinized form of Old English Æðelðryð, literally "noble might," from æðele "noble" (see atheling) + ðryð "strength, might," from Proto-Germanic *thruthitho- "strength" (source also of Old Norse Þruðr, name of the daughter of Thor). Popularized by the reputation of Saint Etheldreda, queen of Northumbria and foundress of the convent at Ely.
