Answer: king

AnswerCrossword Clue
KINGMattress choice
KINGCheckmate capture
KINGChess piece that starts on its opposite color square
KINGChecker double-decker
KINGPiece involved in castling
KING"Love is the key to the solution of the problems of the world." (1964)
KINGCNN regular
KINGWenceslaus, e.g.
KINGBig cheese
KINGCheckmate victim
KINGMonarch
KINGLear or Midas
KINGRoyal flush card
KING"Misery" writer
KINGJuan Carlos, for one
KINGB.B. of blues
KINGPowerful checkers piece
KINGReign man
KINGSaul of Israel, e.g.
KINGPrincess' dad
kingto play the king; behave in an imperious or pretentious manner
KINGRuler on a throne
KINGDouble-decker checker
KINGBoard member?
KINGChess piece
KINGCard
KINGHotel room option
KINGBack-row piece
KINGJanuary honoree
KINGCheckers goal
KINGLear or Tut
KINGAuthor of 14A
KINGBig man on a board
KINGCrowned checker
KINGDouble checker?
KINGGoal in checkers
KINGCertain monarch
KINGHigh card
KINGPowerful pair of checkers
KINGQueen's spouse