A word appearing N. chwiniol “whirling, giddy, mad, fantastic” in The Etymologies of the 1930s, an adjectival form of N. chwinia- “twirl, whirl, eddy” (Ety/SWIN; EtyAC/SWIN). The gloss “mad” was missing from The Etymologies as published in The Lost Road (LR/388) but was noted by Carl Hostetter and Patrick Wynne in their Addenda and Corrigenda to the Etymologies (VT46/16).

Neo-Sindarin: Many Neo-Sindarin writers adapted this word as ᴺS. hwiniol “whirling, giddy, mad, fantastic” since ancient initial sw became hw in Sindarin of the 1950s and 60s rather than chw as it did in Noldorin of the 1930s and 40s. I prefer ᴺS. whiniol as more consistent with Tolkien’s orthography in the 1950s and 60s.