Gehenna

(originally Ge bene Hinnom; i.e., "the valley of the sons of
Hinnom"), a deep, narrow glen to the south of Jerusalem, where
the idolatrous Jews offered their children in sacrifice to
Molech (2 Chr. 28:3; 33:6; Jer. 7:31; 19:2-6). This valley
afterwards became the common receptacle for all the refuse of
the city. Here the dead bodies of animals and of criminals, and
all kinds of filth, were cast and consumed by fire kept always
burning. It thus in process of time became the image of the
place of everlasting destruction. In this sense it is used by
our Lord in Matt. 5:22, 29, 30; 10:28; 18:9; 23:15, 33; Mark
9:43, 45, 47; Luke 12:5. In these passages, and also in James
3:6, the word is uniformly rendered "hell," the Revised Version
placing "Gehenna" in the margin. (See HELL T0001731; HINNOM
T0001790.)