(not in technical use) a gear tooth, formerly esp. one of hardwood or metal, fitted into a slot in a gearwheel of less durable material.

a cogwheel.

a person who plays a minor part in a large organization, activity, etc.

He's just a small cog in the financial department.

(of an electric motor) to move jerkily.

to roll or hammer (an ingot) into a bloom or slab. ?

slip a cog

to make a blunder; err

One of the clerks must have slipped a cog.

noun

cogwheel , differential , fang , gear , pinion , prong , rack , ratchet , tine , tooth , transmission , tusk , wheel , cajole , cam , catch , cheat , connect , deceive , deception , fraud , lie , subordinate , tenon , trick , wedge , wheedle