# hydraulic

/haɪˈdɹɔɫɪk/ (US) · /haɪdɹˈɔːlɪk/ (UK)

Source: https://englishreference.com/word/hydraulic
Updated: 2026-06-20

## Senses

### 1. operated by liquid pressure

adjective · CEFR B2 · Technical

describes a machine or tool that works by using liquid under pressure to move its parts.

For teachers: relating to or operated by the pressure of a liquid, such as oil or water, moving through a confined space.

- The mechanic had to fix the hydraulic brakes on the truck because they were leaking oil.
- The aircraft's hydraulic system failed during the descent, forcing the pilot to rely on the mechanical backup to lower the landing gear.

Usage: Usually placed before the noun it describes.

### 2. related to water

adjective · CEFR C1 · Technical · Academic

having to do with water or the way water moves.

For teachers: pertaining to water in motion or the study of water engineering.

- Engineers studied the hydraulic flow of the river to prevent flooding in the town.
- The city invested in a new hydraulic infrastructure to manage the seasonal overflow from the surrounding mountain streams.

Usage: Common in engineering and environmental science contexts.

### 3. to mine with water

verb · CEFR C2 · Technical · Archaic

to use high-pressure water to wash away earth and find minerals like gold.

For teachers: to conduct mining operations by using high-pressure jets of water to dislodge rock material or move sediment.

- During the gold rush, many miners began to hydraulic the hillsides, which caused a lot of damage to the land.
- Nineteenth-century companies would hydraulic entire mountainsides to extract gold, leading to significant environmental degradation and downstream siltation.

Usage: This transitive verb is primarily used in historical or specialised mining contexts.

## Examples

- The mechanic checked the hydraulic brakes on the truck.
- The construction crew used a hydraulic lift to move the heavy steel beams to the top floor.
- Modern aircraft rely on sophisticated hydraulic systems to actuate landing gear and flight control surfaces, ensuring precise movement under extreme atmospheric pressure.

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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.