What does 2 Chronicles 24:25 mean?

When the Syrians left Joash badly wounded, his own officials plotted against him for killing Jehoiada's son. They murdered him in his bed. He was buried in the City of David, but not in the royal tombs. 2 Chronicles 24:25 - Modern Text Bible

(Joash's own people turned on him, and he died in disgrace, not even given the honor of a royal burial.)