Words related to rotund
1731, from Medieval Latin rotarius "pertaining to wheels," from Latin rota "a wheel, a potter's wheel; wheel for torture," from PIE root *ret- "to run, to turn, to roll" (source also of Sanskrit rathah "car, chariot;" Avestan ratho; Lithuanian ratas "wheel," ritu "I roll;" Old Irish roth, Welsh rhod "carriage wheel"). The root also forms the common West Germanic word for "wheel" (originally "spoked wheel"): Old High German rad, German Rad, Dutch rad, Old Frisian reth, Old Saxon rath.
The international service club (founded by Paul P. Harris in Chicago in 1905) is so called from the practice of clubs entertaining in rotation. Hence Rotarian (1911).
"round building," especially one with a dome, 1680s, from Italian rotonda, typically in reference to the Pantheon, the most celebrated building of this kind, from noun use of Latin rotunda, fem. of rotundus "round" (see rotund). Meaning "circular hall or room within a building" is from 1780.