An adjective glossed “rushing, noisy, loud, rustling or splashing” from the Gnomish Lexicon of the 1910s, an elaboration of its noun form G. gwass (GL/44).
Gnomish
gwass
noun. rush, rushing, noise of rushing, splash
gwassiol
adjective. rushing, noisy, loud, rustling or splashing
A noun glossed “rush, rushing, noise of rushing, splash” from the Gnomish Lexicon of the 1910s (GL/44), clearly a derivative of the root ᴱ√GWASA (QL/103).