A verb appearing as G. ilt- “to yoke, join” in the Gnomish Lexicon of the 1910s (GL/50), likely based on the early root ᴱ√YḶTḶ (QL/106).
Neo-Sindarin: For purposes of Neo-Eldarin I adapt this early root as ᴺ√YALTA “yoke”, so I would adapt the Gnomish verb as ᴺS. ialtha- “to yoke”. For “to join” I would use ᴺS. ianna-.
A verb in the Gnomish Lexicon of the 1910s given as {galta- >>} galtha- “kindle”, apparently a transitive or causative variant of G. gal- “shine (golden)” (GL/37).