The heart of Mount Doom, translated “Chambers of Fire” (LotR/942), a combination of the class-plural of sam “chamber” and the noun naur “fire”.
Sindarin
Sammath Naur
place name. Sammath Naur
sammath naur
place name. Chambers of Fire
Elements
Word Gloss sam “chamber, chamber, [G.] room” naur “fire, fire, [N.] flame”
Sammath Naur
noun. chambers of fire
sam(b) (“chamber, room”) + ath (collective plural suffix), naur (“fire”)
topon. >> naur