5. (Mech.) A cogwheel with a small number of teeth, or leaves, adapted
to engage with a larger wheel, or rack (see Rack); esp., such a wheel
having its leaves formed of the substance of the arbor or spindle which
is its axis.
Lantern pinion. See under Lantern. -- Pinion wire, wire fluted
longitudinally, for making the pinions of clocks and watches. It is
formed by being drawn through holes of the shape required for the
leaves or teeth of the pinions.
Pin"ion (?), v. t. [imp. & p. p. Pinioned (?); p. pr. & vb. n.
Pinioning.] 1. To bind or confine the wings of; to confine by binding
the wings. Bacon.