Beware, older languages below! The languages below were invented during Tolkien's earlier period and should be used with caution. Remember to never, ever mix words from different languages!

Gnomish

molnaith

noun. molar

A noun appearing as G. molnaith “molar” in the Gnomish Lexicon of the 1910s, a combination of G. môl “mouth” and G. naith “tooth” (GL/41).

Neo-Sindarin: I would adapt this as ᴺS. molnel “molar” for purposes of Neo-Sindarin, using the later word [N.] nêl for “tooth”, and with the initial element reconceived of as [ᴺS.] mol- “grind”.