h₂welh₁-tó-
“rolled, turned over”vault, revolt, volute, evolution
Participial of *h₂welh₁- giving Latin volvere participle: vault, revolt, volute, evolution.
Discussion
The form *h₂welh₁-tó- is a verbal adjective built on the root *h₂welh₁- "to turn, to roll," with the participial suffix *-tó- marking a state resulting from the action of the verb — hence "rolled, turned over." Pokorny (IEW 1140–1144) reconstructs a broad semantic field under *wel- encompassing turning, winding, and rolling motions, while Rix (LIV² 290) refines the root to *h₂welh₁- with a laryngeal that surfaces in the full-grade forms of the daughter languages.
The Latin reflex volvere "to roll" is among the most productive descendants. From it flow vault (originally a vaulted or rolled arch), revolve and revolt (to roll back or turn against), evolution (an unrolling), involve (to roll into), and volume, which in its earliest Latin sense meant a rolled scroll of papyrus — the physical form in which ancient texts were read by unrolling one end while rolling up the other. The semantic journey from a rolled manuscript to an abstract measure of quantity or a bound book illustrates how material culture reshapes inherited vocabulary. German walzen and ultimately the familiar English waltz — a dance whose very name preserves the ancient motion of turning — continue the root through Germanic *waltōną "to roll, to turn."
The participial formation *h₂welh₁-tó- thus captures a moment of completion: something that has been turned over, wound around, or set into circular motion, a meaning that radiates outward through millennia of phonological change into words for dance, architecture, political upheaval, biological development, and the written word itself.