Opposite words for king:
queen regnant, inferior, queen, small-timer, half-pint, nobody, female monarch, nothing, lightweight, zero, subordinate, underling.
Usage samples:
  1. But the King shook his head.
    "Martin Pippin in the Apple Orchard", Eleanor Farjeon.
  2. Kamrasi, the former king of Unyoro, was dead, and had been succeeded by his son, Kabba Rega.
    "Ismailia", Samuel W. Baker.
  3. One and all agreed that they would, in fact, seek their night's lodging just where the King had indicated.
    "Spanish Life in Town and Country", L. Higgin and Eugène E. Street.
  4. How long is the Prince to be with you, Mrs. King?
    "The Prince of Graustark", George Barr McCutcheon.