A girl, a woman; especially a prostitute. Later also: the girlfriend of a thief or criminal.
Origin
Mid 18th century; earliest use found in Session Papers Old-Bailey. Probably from Angloromani (English Romani) mónoshi woman, wife from Romani månuš man (from Sanskrit manuṣya human being, man, (in later use) male person) + -ī feminine suffix. In form mollisher with dissimilation of the second consonant or after moll.