Milcom means “their king.”

Meaning:

Milcom is a biblical name of Ammonite origin, symbolizing rulership or authority. It reflects themes of idolatry and false worship.

Notable References:

Milcom is mentioned in the Bible as the false god of the Ammonites, whose worship was condemned by God, as described in 1 Kings 11:5, 33. The name signifies false kingship in contrast to the true God.