1570s, from Middle French rondelet, diminutive of rondel "short poem with a refrain," literally "small circle," diminutive of Old French rond "circle, sphere," originally an adjective from roont (see round (adj.)). Spelling developed by association with lay (n.1) "poem to be sung."
roulette
round
round robin
roundabout
roundel
roundelay
rounder
Roundhead
roundhouse
roundness
round-table