Cam

How to spell cam

3 letters · 1 syllable

How to pronounce cam

What does cam mean?

1. nounA rotating or sliding shaped piece in a machine that converts rotary motion into linear motion by pushing against a follower.
2. nounAn informal short form of camera, especially a webcam or small mounted video camera.

Cam in a sentence

• The worn cam on the engine stopped the valve from opening fully.

• She switched on her cam before joining the video meeting.

• Each lobe of the cam lifts the follower at a precise moment.

• The dash cam recorded the whole accident from the windscreen.

Where does cam come from?

Language of origin: Dutch

The mechanical sense of cam comes from the Dutch word kam, which literally meant 'comb'. Early cog wheels carried rows of projecting teeth that looked rather like the teeth of a comb, and engineers borrowed the word in the 1700s for the shaped lobe or wheel that pushes a follower in a regular pattern, turning round-and-round motion into back-and-forth motion. From this came the modern engine 'camshaft', the rotating bar studded with cams that open and close the valves. A quite separate modern sense of cam is simply a clipped form of 'camera', popularised by 'webcam' and 'dashcam' in the late twentieth century. Because the word is short and the spelling is fully phonetic, both senses are written exactly the same way and present almost no spelling difficulty.

How the word is built

• cam (whole word, from Dutch kam meaning comb; no affixes)