√THŪ root. “blow, cause an air movement”
Tolkien used a variety of related roots for “wind” and “breath”, intermingled with the name Q. Súlimo, surname of Manwë. The earliest of these roots was ᴱ√SUHYU “air, breath, exhale, puff” with variants ᴱ√SUHU and ᴱ√SUFU from the Qenya Lexicon of the 1910s, having derivatives like ᴱQ. sú “noise of wind”, ᴱQ. súma “nostril”, and ᴱQ. †súye “air, breezes, winds” (QL/86). Related forms in the contemporaneous Gnomish Lexicon confirm that the root began with S-, such as: G. saul “a great wind”, G. sû, G. and sûtha- “blow (of wind)” (GL/67-68). In Early Noldorin Word-lists from the 1920s Tolkien twice mentioned ᴱ√suru “(to) blow” as the basis for ᴱN. huiriaith “gale” (PE13/148, 163).
In The Etymologies of the 1930s Tolkien instead had ᴹ√THŪ “puff, blow” with derivatives like ᴹQ. súle/N. thûl “breath” and ᴹQ. súya-/N. thuia- “breathe” (Ety/THŪ). A document grouped with Quenya Notes (QN) from 1957 had an extensive discussion of Q. súlë “spirit; breath” where he gave the root as √THŪ with variant √SŪ (PE17/124). In notes on spirit from 1957, however, Tolkien indicated that √THŪ and √SŪ were similar distinct roots, the former being “blow, cause an air movement” and the latter “blow, move with audible sound (of air)” (NM/237), that is the distinction being the absence or presense of sound. These notes also noted various extensions to these base roots such as √THUS and √SUR of similar meaning (NM/237).
The root √SŪ was mentioned in Notes on Galdriel’s Song (NGS) from the late 1950s or early 1960s, along with extended form √SUR(U) serving as the basis for Q. súrë “wind” (PE17/62). In notes from the late 1960s, ✶sū was mentioned a couple times as an example of an ancient monosyllabic noun with the meaning “(noise of) wind” (VT47/12, 35). In one of these documents Tolkien clarified that base form ✶sū was “used only of the sound of wind; as noun [for actual ‘wind’] + r/l: suli, sur(i)” (VT47/12). Compare Q. súrë above as well as S. sûl “wind” (PE17/15; RC/778).
Thus it seems clear that Tolkien’s later writings, he had two distinct but related roots having to do with the movement of air: √THŪ “blow without sound, breath” and √SŪ “blow with sound, (noise of) wind”.
References ✧ NM/237; PE17/124, 187
ᴹ√THŪ root. “puff, blow”
References ✧ Ety/THŪ, THUS