Short for Tammy Shanter, corruption of next.
1894. Lucy B. Walford, Matchmaker, xliv. The letter was foand inside the inner brim of his Tammy.
1896. Westm. Gaz., 26 Sept., 7/2. The Burns Statue . The poet stands in an easy attitude . He wears the tammy, the ploughmans coat and breeches, and the rough Scotch stockings.