“Hammelech” From Boyd’s Bible Dictionary:
(king). Hardly a proper name (Jer. 36:26; 38:6).
“King” From Boyd’s Bible Dictionary:
(tribe). Title of Hebrew rulers from Saul to Zedekiah, B. C. 1095-588. Other rulers (Gen. 36:31; Ex. 3:19; Num. 31:8). Supreme ruler (1 Tim. 1:17; 6:15).
Concise Bible Dictionary:
Father of Jerahmeel and Malchiah, as in the AV. The word is considered by some not to be a proper name, but to signify “the king,” reading “Jerahmeel, the king’s son,” and “Malchiah, the king’s son” (Jer. 36:26; Jer. 38:6); as in the margin and the RV.
Strong’s Dictionary of Hebrew Words: