From cagar; a fastener, i.e. (of a person) a smith, (of a thing) a prison -- prison, smith.
see HEBREW cagar
H4525. masger
מַסְגֵּר noun [masculine]
1 locksmith, smith.
2 dungeon: — always absolute:
1 collective smiths, ׳וְהַמּ וְכָלהֶֿחָרָשׁ 2 Kings 24:14 compare 24:16, Jeremiah 24:1; 29:2.
2 dungeon Isaiah 24:22 (compare סגר Pu`al); figurative of exile 42:7 (מִמּ ׳הוֺצִיא); מִמּ ׳הוֺצִיאָה נַפְשִׁי Psalm 142:8.