Variant of Rosalyn. Roslyn is a variant of the name Rosalyn, ultimately derived from Rosalind. Rosalind originates in Germanic languages and means "delicate, gentle horse". The original spelling was Rosalynde and only in the Middle Ages, influenced by Latin rosa linda, meaning "pretty rose", it changed into Rosalind. It was popularized in Edmud Spenser"s The Shepheardes Calendar, and later on in Shakespeare"s As You Like It. Rosalind is the name of a moon of Uranus, as well as a play by J. M. Barrie.
