(Greek), Tartarus (Latin). That part of the infernal regions where the wicked are punished. (Classic mythology.)
The word “Hell” occurs seventeen times in the English version of the New Testament. In seven of these the original Greek is “Gehenna,” in nine “Hades,” and in one instance it is “Tartaros” (2 Peter ii. 4) It is a very great pity that the three words are translated alike, especially as Gehenna and Hades are not synonymous, nor should either be confounded with Tartarus. The Anglo-Saxon verb hél-an means to cover, hence hell = the grave or Hades.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894