Gehenna

“Fire, Eternal or Hell” From Dictionary of Biblical Words:

It is among the terms Scripture employs to express the endless punishment or torment of the lost, the lake of fire or second death (in contrast with the resurrection and life) where their worm dieth not, and the fire is not quenched. The Old Testament chiefly dwells on temporal judgment here below; the new, characteristically, though not exclusively, on everlasting punishment in hell or gehenna.

“Hell” From Dictionary of Biblical Words:

is etymologically a “covered” place, and means same as Hades. It is commonly used, however, of the place of final punishment, i.e., Gehenna, or the lake of fire. When we read of the Lord, “Thou wilt not leave my soul in hell,” Hades is meant, as elsewhere.

Boyd’s Bible Dictionary:

[HINNOM

Concise Bible Dictionary:

See HELL.

Jackson’s Dictionary of Scripture Proper Names:

hell (from "the valley of Hinnom," see Hinnorn)