This and similar roots were the basis for “wind” words for much of Tolkien’s life, especially in Sindarin and its precursors. Its first appearance was unglossed ᴱ√GWĀ in the Qenya Lexicon of the 1910s with derivatives like ᴱQ. ’wā “wind” and ᴱQ. ’wanwavoite “windy”, where presumably the ’ indicated the lost initial g; there were also two erased variants of the root ᴱ√WĀ and ᴱ√WA’A (WAƷA?) (QL/102). In the contemporaneous Gnomish Lexicon it had derivatives like G. gwâ “wind” and G. gwavwed “windy” (GL/43).
In The Etymologies of the 1930s Tolkien gave the root as ᴹ√WĀ “blow” with extended variants ᴹ√WAIWA and ᴹ√WAWA and derivatives like ᴹQ. vaiwa/N. gwaew “wind” (Ety/WĀ). ᴹQ. ván/N. gwaun < ᴹ√WĀ-N also seem to be related (Ety/WA-N; EtyAC/WA-N), perhaps based on the noise the goose makes. The root √WĀ appeared a number of times in Tolkien’s later writings with glosses like “blow” (PE17/33), “[used?] of noise of wind” (PE17/34), “echoic representation of sound of wind” (NM/237), and in the variant form √WAY “blow, or be disturbed” (PE17/33) or √WAY “blow (as of wind)” (PE17/154, 189). √WAY was its most common variant form, but it had many others such as √WAW, √WIW, √SWA, √SWAW and √SWAR.
Theoretical initial element in ancient wādelo “those who departed Middle-earth”, but according to Tolkien this was a false etymology (WJ/364).