The Collaborative International Dictionary of English v.0.48:

pastor \pas"tor\ (p[.a]s"t[~e]r), n. [L., fr. pascere, pastum,
   to pasture, to feed. Cf. Pabulum, Pasture, Food.]
   1. A shepherd; one who has the care of flocks and herds.
      [1913 Webster]

   2. A guardian; a keeper; specifically (Eccl.), a minister
      having the charge of a church and parish.
      [1913 Webster]

   3. (Zool.) A species of starling (Pastor roseus), native of
      the plains of Western Asia and Eastern Europe. Its head is
      crested and glossy greenish black, and its back is rosy.
      It feeds largely upon locusts.
      [1913 Webster]

WordNet (r) 3.0 (2006):

pastor
    n 1: a person authorized to conduct religious worship;
         "clergymen are usually called ministers in Protestant
         churches" [syn: curate, minister of religion,
         minister, parson, pastor, rector]
    2: only the rose-colored starlings; in some classifications
       considered a separate genus [syn: Pastor, subgenus
       Pastor]

Moby Thesaurus II by Grady Ward, 1.0:

36 Moby Thesaurus words for "pastor":
   DD, Doctor of Divinity, Holy Joe, abbe, bishop, canon, chaplain,
   churchman, churchwoman, clergyman, clergywoman, cleric, clerical,
   clerk, curate, cure, divine, ecclesiastic, father, man of God,
   military chaplain, minister, padre, parson, priest, rector,
   reverend, servant of God, shepherd, sky pilot, supply clergy,
   supply minister, the Reverend, the very Reverend, tonsured cleric,
   vicar