swallow-tail

Noun

swallowtail (plural swallowtails)

1. The forked tail of a swallow.
2. Anything, such as a burgee, of a similar forked shape.
3. A type of tailcoat with two long tapering tails.
   • They have a peculiar style of dress which they wear among themselves, a close-fitting white shirt with black trousers, and a black frock or upper shirt. The women seem to prefer a dress entirely black. On festivals and state occasions they adopt the swallow-tail coat, chimney-pot hat, and their...1869, Alfred Russel Wallace, The Malay Archipelago, volume I, London: Macmillan and Co., page 471
4. Any of various butterflies of the family Papilionidae, many of which have a long extension to each hindwing.
   • Here I obtained the rare and beautiful swallow-tail butterflies, Papilio aenomaus and P. liris; the males of which are quite unlike each other, and belong in fact to distinct sections of the genus, while the females are so much alike that they are undistinguishable on the wing, and to an uneducated...1869, Alfred Russel Wallace, The Malay Archipelago, volume I, London: Macmillan and Co., page 297