- (not in technical use) a gear tooth, formerly especially 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.
Origin of cog1
- any of the teeth or projections on the rim of a gearwheel or sprocket
- a gearwheel, esp a small one
- a person or thing playing a small part in a large organization or process
- (tr) metallurgy to roll (cast-steel ingots) to convert them into blooms
- slang to cheat (in a game, esp dice), as by loading a dice
- a tenon that projects from the end of a timber beam for fitting into a mortise
- (tr) to join (pieces of wood) with cogs
Word Origin and History for slip a cog
c.1300, "cog wheel;" late 14c., "tooth on a wheel," probably a borrowing from a Scandinavian language (cf. Norwegian kugg "cog") and cognate with Middle High German kugel "ball."
Idioms and Phrases with slip a cog
slip a cog
Also, slip a gear or one's gears. Lose one's ability to reason soundly or make correct judgments, as in She must have slipped a cog or she would never have gone out barefoot in December, or What's the matter with him? Has he slipped his gears? These slangy usages allude to a mechanical failure owing to the cog of a gear or a gear failing to mesh. The first dates from about 1930, the variant from the 1960s.