Galactic \Ga*lac"tic\, a. [Gr. ? milky, fr. ?, ?, milk. See {Galaxy}, and cf. {Lactic}.] 1. Of or pertaining to milk; got from milk; as, galactic acid. 2. Of or pertaining to the galaxy or Milky Way. {Galactic circle} (Astron.), the great circle of the heavens, to which the course of the galaxy most nearly conforms. --Herschel. {Galactic poles}, the poles of the galactic circle.