Cam

Webster's Condensed Dictionary- A Condensed Dictionary of the English Language · 1909 · p. 87

kam, n. (Much.) A projecting part of a wheel, etc., giving an alternating motion to a piece pre ing against [D. kam, a comb, ridge, G. kamm. comb, cog.] — Cam'-wheel, n. A wheel of regular outline, producing a variable motion.