late 14c., from Late Latin cyclus, from Greek kyklos "circle, wheel, any circular body, circular motion, cycle of events," from PIE kw(e)-kwl-o-, suffixed, reduplicated form of root *kwel- (1), also *kwele-, "to roll, to move around, wheel" (cognates: Sanskrit cakram "circle, wheel," carati "he moves, wanders;" Avestan caraiti "applies himself," c'axra "chariot, wagon;" Greek polos "a round axis" (PIE *kw- becomes Greek p- before some vowels), polein "move around;" Latin colere "to frequent, dwell in, to cultivate, move around," cultus "tended, cultivated," hence also "polished," colonus "husbandman, tenant farmer, settler, colonist;" Lithuanian kelias "a road, a way;" Old Norse hvel, Old English hweol "wheel;" Old Church Slavonic kolo, Old Russian kolo, Polish koło, Russian koleso "a wheel").

1842, "revolve in cycles," from cycle, n.. Meaning "to ride a bicycle" is from 1883. Related: Cycled; cycling.