Meaning & use
cog
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Meanings
nouncountable
One of the raised teeth around the edge of a wheel that fit into another wheel's teeth so that one can drive the other.
Grammar: Plural cogs: a worn cog can stop a whole gearbox.
Patterns
- a cog on something
- a cog in something
The clockmaker replaced a broken cog in the pocket watch.
Each cog turned the next one, passing the movement along the chain.
A bicycle mechanic noticed that one cog on the rear wheel was worn smooth.
nouncountableinformal
A toothed wheel itself, a gear.
Grammar: Less precise than the first sense; often said of any gear wheel in a machine.
Patterns
- a large cog
- the cogs of something
He opened the old music box and showed us the tiny brass cog inside.
The cogs of the mill ground slowly in the dark.
A cog slipped and the whole mechanism froze.
nouncountablefigurativedisapproving
A person who plays a small, easily replaced part in a large organization or system.
Grammar: Almost always in the phrase a cog in the machine, and it often sounds dismissive.
Patterns
- a cog in something
- a cog in the machine
After ten years of filing forms, she felt like a cog in a vast machine.
He refused to be just another cog in the corporate wheel.
Every cog in the department was told the new rules would apply to them.
Word forms
| plural | cogs |
|---|
Common combinations
- cog in the machine
- Many new employees fear becoming a cog in the machine.
- cog in the wheel
- The minor official was only a cog in the wheel of government.
- cog and wheel
- The old clock showed every cog and wheel behind the glass.
- worn cog
- A worn cog was the cause of the grinding noise.
- replace a cog
- The repairer had to replace a cog before the toy would work.
Synonyms and how they differ
- gear
- Gear is the everyday engineering word for a toothed wheel, while cog often points to a single tooth or to the figurative idea of a small part.
- tooth
- Tooth means just the individual projection, whereas cog can mean the whole wheel in casual use.
- sprocket
- A sprocket has teeth that grip a chain, as on a bicycle, rather than meshing with another toothed wheel.
Word family
Commonly confused: cog or cock? cog or cough?
cog vs cock
A cock is a male bird or a tap, and the word is also vulgar slang; it only looks and sounds somewhat like cog, which names a gear tooth.
cog vs cough
Cough names the reflex of clearing the throat and is spelled with ough; cog is a short word for a gear tooth.
Practice
Which sentence uses cog in its figurative sense?
Choose one answer.
Only the third sentence uses cog for a person with a small, replaceable role. The other three describe actual toothed parts of mechanisms.
Make it your own
Write a sentence using “cog”, then check it and compare it with the examples above.