Gnomish
dolmeg
noun. mole
dolfa
noun. mole
doldrin
noun. mole
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
A noun appearing as G. {doldos >>} dolfa and {doldrin >>} dolmeg in the Gnomish Lexicon of the 1910s, derived from the early root ᴱ√NDOLO “delve” (GL/30). The form G. doldrin “mole” appeared undeleted in the Gnomish Grammar and the Official Name List for the Lost Tales (GG/8; PE13/104).
Neo-Sindarin: For purposes of Neo-Sindarin I would adapt these words as ᴺS. dolph, reconceived of as a derivative of the root ᴹ√NDOL “✱hill, head”, describing these creatures as hill-makers.