Beguin Family History

French (also Béguin): from a diminutive of the ancient Germanic personal name Bego a short form of compound names based on the element beg from Latin beccus ‘beak bill’.

Nickname from beguin the name for a member of a medieval Christian male religious community (ultimately named after a priest called Lambert le Begue; see Begue) that followed a monastic rule without making perpetual vows and was quickly considered heretic;

by extension the term came to mean ‘sanctimonious person’.