Progne \Prog"ne\, n. [L., a swallow, traditionally said to be fr. Progne (The sister of Philomela), who was changed into a swallow, Gr. ?.] (Zo["o]l.) (a) A swallow. (b) A genus of swallows including the purple martin. See {Martin}. (c) An American butterfly ({Polygonia, or Vanessa, Progne}). It is orange and black above, grayish beneath, with an L-shaped silver mark on the hind wings. Called also {gray comma}.