An apparatus (consisting formerly of a sheet of canvas stretched on a frame, now usually of an arrangement of boards) attached to each of the arms…

An appliance or appendage resembling or analogous to a wing in form or function. One of the floats of a waterwheel or sails of a windmill.

Something acting as a sail or fan. Obsolete.

A sail of a windmill.

A sail of a windmill. Also occasionally a paddle of a waterwheel.

Any of the sails or (now sometimes) blades of a windmill. Usually in plural. Cf. windmill arms n. at windmill, n. compounds 1b.

A sail of a windmill.

(a) the sail of a windmill (= vane, n. 3a); (b) a weathercock (= vane, n. 1).

The sail of a windmill. dialect.

The sail of a windmill: = van, n.1 5.

Applied to mechanical contrivances that have a quick revolution. A sail of a windmill; also plural ‘the fan-wheel on the vane of a windmill cap which…

A sail of a windmill; = fan, n.1 6c (Cf. vane, n. 3a.)