# osmosis

/ˌɔzˈmoʊsɪs/ (US) · /ɒzmˈəʊsɪs/ (UK)

Source: https://englishreference.com/word/osmosis
Updated: 2026-08-27

## Senses

### 1. scientific process

noun · CEFR C1 · Technical

the way water or other liquids move through a thin skin or membrane from a weak mixture to a strong one.

For teachers: the spontaneous net movement of solvent molecules through a semipermeable membrane into a region of higher solute concentration.

- The plant roots take in water from the soil through osmosis.
- In reverse osmosis, pressure is applied to overcome osmotic pressure, allowing for the desalination of seawater for human consumption.

Usage: Uncountable in general scientific contexts; countable when referring to specific instances or experiments.

## Examples

- Osmosis helps plants absorb water from the soil.
- During the biology lab, students observed how osmosis causes potato slices to swell when placed in distilled water.
- The kidneys rely on the principle of osmosis to regulate the body's fluid balance, ensuring that excess water is excreted while essential electrolytes remain within the bloodstream.

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