To overtake someone while driving when your engine is at the amount of revs that offer peak acceleration so that the slower vehicle is dispatched in the minimum amount of time (when the engine in on the "cam"). This is best demonstrated in a car with a manual gearbox by dropping a gear or two in order to raise the engine revs.
"I'm sick of being stuck behind this guy. After the next bend I'm going to do a bit of camming on him."
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