Cam

Cam Cam (k[a^]m), n. [Dan. kam comb, ridge; or cf. W., Gael., and Ir., cam bent. See 1st {Comb}.] 1. (Med.) (a) A turning or sliding piece which, by the shape of its periphery or face, or a groove in its surface, imparts variable or intermittent motion to, or receives such motion from, a rod, lever, or block brought into sliding or rolling contact with it. (b) A curved wedge, movable about an axis, used for forcing or clamping two pieces together. (c) A projecting part of a wheel or other moving piece so shaped as to give alternate or variable motion to another piece against which it acts. [1913 Webster]

Note: Cams are much used in machinery involving complicated, and irregular movements, as in the sewing machine, pin machine, etc. [1913 Webster]

2. A ridge or mound of earth. [Prow. Eng.] --Wright. [1913 Webster]

{Cam wheel} (Mach.), a wheel with one or more projections (cams) or depressions upon its periphery or upon its face; one which is set or shaped eccentrically, so that its revolutions impart a varied, reciprocating, or intermittent motion. [1913 Webster]