Qenya
nelet
noun. tooth
nele
noun. tooth
nelde
cardinal. three
nelke
noun. tooth
karka
noun. tooth
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!
nelet
noun. tooth
nele
noun. tooth
nelde
cardinal. three
nelke
noun. tooth
karka
noun. tooth
The normal Quenya word for “tooth”, appearing in The Etymologies written around 1937 derived from the root ᴹ√NELEK of the same meaning (Ety/NÉL-EK), where the final k became t. Its plural form nelki [nelci] indicates a stem form of nelk- [nelc-], since in most inflected forms the word would undergo the Quenya syncope and loose the second e. A variant form nelke (EtyAC/NÉL-EK) may reflect a reformation to align with those inflected forms.
Conceptual Development: In the Qenya Lexicon of the 1910s Tolkien had ᴱQ. nele (neli-) “tooth” under the early root ᴱ√NELE (QL/65), a word also mentioned in the contemporaneous Gnomish Lexicon (PME/65). In Early Qenya Word-lists of the 1920s Tolkien instead had ᴱQ. nyat “tooth” (PE16/136), but that seems to have been a transient idea. ᴹQ. nelet first appeared in Common Eldarin: Noun Structure from 1936 alongside variant nelke, but it was replaced by nele and then later nelke was deleted as well (PE21/56 and note #12). Both nelet and variant nelke were restored in The Etymologies (see above).
Primitive √nelek “tooth” was mentioned in Common Eldarin: Noun Structure from the early 1950s, but its Quenya derivatives were not listed.
Neo-Quenya: For purposes of Neo-Quenya, I’d use nelet (nelc-) “tooth” as the traditional form of this word, with nelcë as a modern variant with more regular inflections.