# gearbox

/ˈɡɪɹˌbɑks/ (US) · /ɡˈiəbɒks/ (UK) · CEFR B2 · Noun

Source: https://englishreference.com/word/gearbox
Updated: 2026-05-07

## Definition

the part of a vehicle or machine that contains the gears. It helps control how much power goes from the engine to the wheels.

For teachers: a set of gears with its casing, especially in a motor vehicle, which transmits power from the engine to the axle. Often used to describe the entire transmission system in automotive contexts.

## Examples

- The car needs a new gearbox because it won't shift into reverse.
- Modern automatic gearboxes use complex sensors to decide exactly when to change gears for the best fuel efficiency.
- The engineer noted that the high-torque requirements of the industrial drill necessitated a reinforced gearbox to prevent the internal teeth from shearing under heavy load.

## Usage notes

- Commonly used in British English; American English often prefers the term 'transmission'.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.