The noun G. cwast “shaking” appeared in the Gnomish Lexicon of the 1910s (GL/28), clearly based on the early root ᴱ√QASA and cognate to ᴱQ. qasa- “shake, flap, nod, rustle” (QL/76).
Neo-Sindarin: Since I retain ᴺQ. quas- “shake” for purposes of Neo-Quenya, I would retain this word for Neo-Sindarin as well, but adapted as ᴺS. past “shaking” with the usual Sindarin sound change of ancient kw to p.
A noun for “dwelling” in the Gnomish Lexicon of the 1910s derived from the early root ᴱ√[[ep|ŋwa[ð]-]] (GL/47).