Definition of swift:
(n) :
the current of a stream; a small plain-colored bird (of the family Micropodidæ) that resembles a swallow and is noted for its rapid flight. Common European swift: Cypselus, ∨ Micropus, apus. The common American, or chimney, swift: Chætura pelagica. The Australian swift: Chætura caudacuta. The European Alpine swift: Cypselus melba. The common Indian swift: Cypselus affinis