\Ur"sa\, n. [L. ursa a she-bear, also, a constellation,
fem. of ursus a bear. Cf. {Arctic}.] (Astron.)
Either one of the Bears. See the Phrases below.

{Ursa Major} [L.], the Great Bear, one of the most
   conspicuous of the northern constellations. It is situated
   near the pole, and contains the stars which form the
   Dipper, or Charles's Wain, two of which are the Pointers,
   or stars which point towards the North Star.

{Ursa Minor} [L.], the Little Bear, the constellation nearest
   the north pole. It contains the north star, or polestar,
   which is situated in the extremity of the tail.