The king’s, the father of Jerahmeel, mentioned in Jer. 36:26. Some take this word as a common noun, “the king”, and understand that Jerahmeel was Jehoiakim’s son. Probably, however, it is to be taken as a proper name.
Jer.38: Then took they Jeremiah, and cast him into the dungeon of Malchiah the son of Hammelech, that was in the court of the prison: and they let down Jeremiah with cords. And in the dungeon there was no water, but mire: so Jeremiah sunk in the mire.