a light cotton cap covering all the hair, worn by women in the 18th and 19th centuries （18、19 世纪的）头巾式女帽 Word Originmid 18th cent.: mob, variant of obsolete mab ‘slut’. The word mob was first used in the sense ‘prostitute’ (mid to late 17th cent.), later denoting a negligee (mid 17th cent. to mid 18th cent.).