Antonyms of seeker:
incumbent, officeholder, awardee, honoree, inductee, dropout, noncandidate.
Examples of usage:
  1. The immortal spirit will ever be satisfied with these things; and the good time will never come to the erring seeker.
    "The Good Time Coming", T. S. Arthur.
  2. " There's no ground here," came a small faint voice from the kneeling Seeker.
    "Prudence of the Parsonage", Ethel Hueston.
  3. He has now become a by- word as a hypocrite and a merciless self- seeker.
    "Slain By The Doones", R. D. Blackmore.