ᴺS. [G.] ^oetha- v. “to lay eggs, nest” (Category: Bird)
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√OHO¹ [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.
Reference ✧ GL/74 ✧ “lay eggs, nest”