Source : Webster's Revised Unabridged Dictionary (1913)

Avocation \Av`o*ca"tion\, n. [L. avocatio.]
   1. A calling away; a diversion. [Obs. or Archaic]

            Impulses to duty, and powerful avocations from sin.
                                                  --South.

   2. That which calls one away from one's regular employment or
      vocation.

            Heaven is his vocation, and therefore he counts
            earthly employments avocations.       --Fuller.

            By the secular cares and avocations which accompany
            marriage the clergy have been furnished with skill
            in common life.                       --Atterbury.

   Note: In this sense the word is applied to the smaller
         affairs of life, or occasional calls which summon a
         person to leave his ordinary or principal business.
         Avocation (in the singular) for vocation is usually
         avoided by good writers.

   3. pl. Pursuits; duties; affairs which occupy one's time;
      usual employment; vocation.

            There are professions, among the men, no more
            favorable to these studies than the common
            avocations of women.                  --Richardson.

            In a few hours, above thirty thousand men left his
            standard, and returned to their ordinary avocations.
                                                  --Macaulay.

Source : WordNet®

avocation
     n : an auxiliary activity [syn: {by-line}, {hobby}, {sideline},
         {spare-time activity}]