A cylinder is, at its core, something that rolls. Greek kýlindros meant 'a roller' — a log or tube used to move heavy objects by rolling them. The word comes from kylíndein, 'to roll', from Proto-Indo-European *kʷel-, one of the most prolific roots in any language, meaning 'to turn' or 'to move around'.
The family reunion of *kʷel- descendants is remarkable. Wheel is the most literal: a thing that turns. Cycle comes via Greek kýklos, 'a circle'. Collar traces through Latin collum, 'neck' — the part of the body that turns. Colony comes from Latin colonus, 'a farmer', one who turns the soil (via colere, 'to cultivate'). Culture itself is turning the
The Greeks originally used kýlindros for practical objects — stone rollers, wooden logs for transporting heavy blocks. The precise mathematical definition (a surface generated by a line moving parallel to a fixed line while tracing a closed curve) came much later.
In German, Zylinder means both 'cylinder' and 'top hat', the tall hat named for its cylindrical silhouette. The word that began with rolling logs across building sites now sits atop formal evening wear.