Origin: English

From Jeffrey, a variant of Geoffrey, from Middle English Geffrey, from an Old French aristocratic name, Geoffroi [dʒɔfreʲ] (> West Middle French Geoffrey, East Middle French Geoffroy), itself from Proto-French forms (latinized in -us) Jotfredus, Jozsfredus, Josfredus (10th century) and Jof[f]redus, Jofridus, Jaufredus, Geffredus (11th century), and ultimately of Proto-Germanic origin. The second element is *friþuz (“peace, sanctuary”). The first element may be *gautaz (“a Geat, a Goth”) [making the Proto-Germanic term *Gautafriþu], as opposed to *gōdaz (“good”) or *gudą (“god”) in Godfrey; this would also make it related to Jocelyn. The name was introduced to England by the Normans in the 11th century.

Etymology: Wiktionary (CC-BY-SA)