noun, masculine/ky.be.ni/plural: culs-bénits
a Holy Joe, a Holy Mary, a zealot, a bigot, a God botherer, a Bible thumper, a Jesus freak, a creeping Jesus, a goody two shoes (an excessively pious person, a sanctimonious person, a holier-than-thou person)
Synonyms: grenouille de bénitier, punaise de sacristie, bondieusard
Literally, “blessed arse”.