Gnomish
usc
noun. fog, mist
func
noun. smoke
huith
noun. fog
usb
noun. fog, mist
usg
noun. fog, mist
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 word for “smoke” in the Gnomish Lexicon of the 1910s, clearly related to G. fug- “smoulder” (GL/36).