The noun king has 10 senses (first 3 from tagged texts)
1. (20) king, male monarch, Rex -- (a male sovereign; ruler of a kingdom)
2. (1) king, queen, world-beater -- (a competitor who holds a preeminent position)
3. (1) baron, big businessman, business leader, king, magnate, mogul, power, top executive, tycoon -- (a very wealthy or powerful businessman; "an oil baron")
4. king -- (preeminence in a particular category or group or field; "the lion is the king of beasts")
5. King, Billie Jean King, Billie Jean Moffitt King -- (United States woman tennis player (born in 1943))
6. King, B. B. King, Riley B King -- (United States guitar player and singer of the blues (born in 1925))
7. King, Martin Luther King, Martin Luther King Jr. -- (United States charismatic civil rights leader and Baptist minister who campaigned against the segregation of Blacks (1929-1968))
8. king -- (a checker that has been moved to the opponent's first row where it is promoted to a piece that is free to move either forward or backward)
9. king -- (one of the four playing cards in a deck bearing the picture of a king)
10. king -- ((chess) the weakest but the most important piece)