Meaning A girl's name of English origin, it means "Variant of Thomasina 'Twin'." Origin of Tamsin English Popular Middle Names Pronunciation 🔊 Listen Tamsin TahMSIHN Similar Names Tammia Sippora Ajaruva Tamzim Tholley Tolyah Shelbe Tamiiya Taviona Taviayha Year by Year Popularity of Tamsin