In a machine: a component that supports a moving part, restricts its motion to that of a particular kind (e.g. rotational), and is designed to…

(a) see friction-roller n.; (b) see quot. 1888.

(a) a roller placed so as to lessen the friction of anything passing over it; (b) see quot. 1888.

one of the balls used to lessen the friction of bearings, etc.

Applied more or less specifically to many cylindrical parts of machines, etc. (with reference either to the internal chamber or external surface); a…

A device, esp. a tap, designed to be operated by being screwed or turned. In later use: spec. a mechanism forming part of a machine for rolling…

A bearing in which the parts are separated by a ring of small, freely rotating, uniform metal balls, used esp. for rotating axles and shafts.

a roller in the form of a long, thin, sometimes tapered cylinder, used in roller bearings.