A verb appearing as G. uitha- “lay eggs, nest” in the Gnomish Lexicon of the 1910s (GL/74), likely derived from the early root ᴱ√OHO [OΧO] which was the basis for ᴱQ. ohte “egg” in the contemporaneous Qenya Lexicon (QL/69). This verb probably represents the vocalization of ancient χ to i before th [θ], after which the resulting oi became ui; compare G. fuitha- “hide” < ᴱ√foχo (GL/36).
Neo-Sindarin: I would adapt this verb as ᴺS. oetha- for purposes of Neo-Sindarin, based on the Neo-Root ᴺ√OKH “egg”, since a similar vocalization of χ occurred in Sindarin, but the resulting oi became oe.
A neologism coined Shihali in a Discord chat from 2018-04-20 as a transitive verb for “to smoke”, based on ✱usuktā- from the root √USUK which is generally used for “smoke” words in Neo-Eldarin. In the phonetic development from ancient ✱usuktā-, [[os|intervocalic [s] became [h] and then vanished]] as usual, while the diphthong ui arose because of [[s|the vocalization of the spirant [x] to [i] before [θ]]] after the [[os|pair of stops [kt] became spirantal [xθ]]]; compare S. nuitha- < ✶nuktā- (WJ/413).