Source : Webster's Revised Unabridged Dictionary (1913)

Seeker \Seek"er\, n.
   1. One who seeks; that which is used in seeking or searching.

   2. (Eccl.) One of a small heterogeneous sect of the 17th
      century, in Great Britain, who professed to be seeking the
      true church, ministry, and sacraments.

            A skeptic [is] ever seeking and never finds, like
            our new upstart sect of Seekers.      --Bullokar.

Source : WordNet®

seeker
     n 1: someone making a search or inquiry; "they are seekers after
          truth" [syn: {searcher}, {quester}]
     2: a missile equipped with a device that is attracted toward
        some kind of emission (heat or light or sound or radio
        waves)