Source : Webster's Revised Unabridged Dictionary (1913)

Vocation \Vo*ca"tion\, n. [L. vocatio a bidding, invitation, fr.
   vocare to call, fr. vox, vocis, voice: cf. F. vocation. See
   {Vocal}.]
   1. A call; a summons; a citation; especially, a designation
      or appointment to a particular state, business, or
      profession.

            What can be urged for them who not having the
            vocation of poverty to scribble, out of mere
            wantonness make themselves ridiculous? --Dryden.

   2. Destined or appropriate employment; calling; occupation;
      trade; business; profession.

            He would think his service greatly rewarded, if he
            might obtain by that means to live in the sight of
            his prince, and yet practice his own chosen
            vocation.                             --Sir. P.
                                                  Sidney.

   3. (Theol.) A calling by the will of God. Specifically:
      (a) The bestowment of God's distinguishing grace upon a
          person or nation, by which that person or nation is
          put in the way of salvation; as, the vocation of the
          Jews under the old dispensation, and of the Gentiles
          under the gospel. ``The golden chain of vocation,
          election, and justification.'' --Jer. Taylor.
      (b) A call to special religious work, as to the ministry.

                Every member of the same [the Church], in his
                vocation and ministry.            --Bk. of Com.
                                                  Prayer.

Source : WordNet®

vocation
     n 1: the particular occupation for which you are trained [syn: {career},
           {calling}]
     2: a body of people doing the same kind of work [syn: {occupational
        group}]