Boyd’s Bible Dictionary:

(fortress of Chemosh). A city on the Euphrates (Isa. 10:5-95O Assyrian, the rod of mine anger, and the staff in their hand is mine indignation. 6I will send him against an hypocritical nation, and against the people of my wrath will I give him a charge, to take the spoil, and to take the prey, and to tread them down like the mire of the streets. 7Howbeit he meaneth not so, neither doth his heart think so; but it is in his heart to destroy and cut off nations not a few. 8For he saith, Are not my princes altogether kings? 9Is not Calno as Carchemish? is not Hamath as Arpad? is not Samaria as Damascus? (Isaiah 10:5‑9); 2 Chron. 35:20-2320After all this, when Josiah had prepared the temple, Necho king of Egypt came up to fight against Carchemish by Euphrates: and Josiah went out against him. 21But he sent ambassadors to him, saying, What have I to do with thee, thou king of Judah? I come not against thee this day, but against the house wherewith I have war: for God commanded me to make haste: forbear thee from meddling with God, who is with me, that he destroy thee not. 22Nevertheless Josiah would not turn his face from him, but disguised himself, that he might fight with him, and hearkened not unto the words of Necho from the mouth of God, and came to fight in the valley of Megiddo. 23And the archers shot at king Josiah; and the king said to his servants, Have me away; for I am sore wounded. (2 Chronicles 35:20‑23); Jer. 46:22Against Egypt, against the army of Pharaoh-necho king of Egypt, which was by the river Euphrates in Carchemish, which Nebuchadrezzar king of Babylon smote in the fourth year of Jehoiakim the son of Josiah king of Judah. (Jeremiah 46:2)).

Concise Bible Dictionary:

Strong’s Dictionary of Hebrew Words:

of foreign derivation; Karkemish, a place in Syria
KJV Usage:

Jackson’s Dictionary of Scripture Proper Names:

the head (or lamb) as if departed

Potts’ Bible Proper Names:

The defense of concealment:―fortified city on the E. side of the Euphrates [CARCHEMISH], 2 Chron. 35:20. {Munimentum recessus}