An ancient monosyllabic noun for the “sound of wind” appearing in notes from the late 1960s, which survived unchanged from its primitive form into modern Quenya (VT47/12, 35). It was derived from the root √SŪ of similar meaning.
Conceptual Development: ᴱQ. sú appeared all the way back in Qenya Lexicon and Poetic and Mythological Words of Eldarissa of the 1910s with the glosses “noise of wind” or “(noise) of wind”, but there it was derived from the early root ᴱ√SUHYU “air, breath, exhale, puff” (QL/86; PME/86). There was no mention of Q. sú in the intervening five decades, however.
sú noun "sound of wind" (VT47:12), "noise of wind" (LT1:266, "Qenya" spelling sû)