The Collaborative International Dictionary of English v.0.48:

Nativity \Na*tiv"i*ty\, n.; pl. Nativies. [F. nativit['e], L.
   nativitas. See Native, and cf. Na["i]vet['e].]
   1. The coming into life or into the world; birth; also, the
      circumstances attending birth, as time, place, manner,
      etc. --Chaucer.
      [1913 Webster]

            I have served him from the hour of my nativity.
                                                  --Shak.
      [1913 Webster]

            Thou hast left . . . the land of thy nativity.
                                                  --Ruth ii. 11.
      [1913 Webster]

            These in their dark nativity the deep
            Shall yield us, pregnant with infernal flame.
                                                  --Milton.
      [1913 Webster]

   2. (Fine Arts) (capitalized) A picture representing or
      symbolizing the early infancy of Christ. The simplest form
      is the babe in a rude cradle, and the heads of an ox and
      an ass to express the stable in which he was born.
      [1913 Webster]

   3. (Astrol.) A representation of the positions of the
      heavenly bodies as the moment of one's birth, supposed to
      indicate one's future destinies; a horoscope.
      [1913 Webster]

   The Nativity, the birth or birthday of Christ; Christmas
      day.

   To cast one's nativity or To calculate one's nativity
      (Astrol.), to find out and represent the position of the
      heavenly bodies at the time of one's birth.
      [1913 Webster]