Origin of the name Tamsin: Contraction of Thomasina, a feminine form of Thomas (a twin), which is derived via the Ecclesiastic Greek and Late Latin, from the Aramaic tē'ōma (a twin). From A World of Baby Names by Teresa Norman.Buy the book.
Tamsen is baby girl name mainly popular in Christian religion and its main origin is English. Tamsen name meanings is Twin. Other similar sounding names can be Tamson.