Rosier, according to A Dictionary Of Angels by Gustav Davidson, is "a former lesser-rank angel of the order of dominations, now officiating in Hell", the cited source being Sebastien Michaelis' Admirable History of the Possession and Conversion of a Penitent Woman (1612). Rosier does not appear in the Bible (or Apocrypha), and is not mentioned in the Catholic Encyclopedia or Britannica, but Rosier is recognized in esoteric tradition as a fallen angel (specifically a Dominion of the Second Sphere), and is considered the patron demon of tainted love and seduction. Rosier is French for "rose tree" or "rose bush", and is a common surname in Francophone countries.
In popular culture
References
Rosier Wikipedia(Text) CC BY-SA