black swallowtail

noun

1. See under swallowtail(def 2).

noun

1. the tail of a swallow or a deeply forked tail like that of a swallow.
2. any of several butterflies of the genus Papilio, characterized by elongated hind wings that resemble the tail of a swallow, as P. polyxenes (black swallowtail).Compare spicebush swallowtail, tiger swallowtail, zebra swallowtail.
3. tail coat.

noun

1. any of various butterflies of the genus Papilio and related genera, esp P. machaon of Europe, having a tail-like extension of each hind wing: family Papilionidae
2. the forked tail of a swallow or similar bird
3. short for swallow-tailed coat