Definition of "Roller" :

noun: a grounder that rolls along the infield

noun: pigeon that executes backward somersaults in flight or on the ground

noun: Old World bird that tumbles or rolls in flight; related to kingfishers

noun: a mechanical device consisting of a cylindrical tube around which the hair is wound to curl it

noun: a cylinder that revolves

noun: a small wheel without spokes (as on a roller skate)

noun: a long heavy sea wave as it advances towards the shore