Translation guide
A cog is a tooth on a gear or a person/thing that is a small part of a larger system. This guide covers how to express these meanings in Japanese.
The physical tooth of a gear or cogwheel.
General word for 'tooth', used for gear teeth. Often combined with 'gear' for clarity.
歯車の歯が欠けた。
A cog on the gear broke off.
Explicit phrase meaning 'tooth of a gear'. Used when precision is needed.
この歯車の歯は摩耗している。
The cogs on this gear are worn down.
A person or thing that is a small, insignificant part of a larger organization or machine.
Literally 'one of the cogs'. Common metaphor for a small part of a system. Neutral to slightly negative nuance.
彼は大きな組織の歯車の一つに過ぎない。
He's just a cog in a large organization.
Directly translating 'cog' as コグ (kogu) is not standard Japanese. Use 歯 (は) for mechanical teeth and 歯車 (はぐるま) for the gear itself. For the metaphorical sense, 歯車の一つ is the natural expression.
Literally 'small cog'. Emphasizes insignificance. Often used in self-deprecating or critical contexts.
自分は社会の小さな歯車だと感じる。
I feel like I'm just a small cog in society.
Means 'member' or 'one of the group'. Less metaphorical, more neutral. Not specifically 'cog', but can be used in similar contexts.
彼はチームの一員として働いている。
He works as a cog in the team.