A pretty country girl; a female sweetheart. Also: a pretty or dexterous female servant.
Originally as a generic proper name in pastoral poetry.
Late 16th century; earliest use found in Robert Greene (bap. 1558, d. 1592), writer and playwright. From the female forename Phyllis, Phillis from classical Latin Phyllis, the name of the daughter of King Sithon of Thrace, who was changed into an almond tree, a stock female name in poetry from Hellenistic Greek Φυλλίς, female name, lit. foliage of a tree from ϕύλλον leaf + -ις.