# algae

/ˈæɫdʒi/ (US) · /ˈælɡiː/ (UK)

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

## Senses

### 1. aquatic organisms

noun · CEFR B2 · Technical

simple organisms that grow in water and use sunlight to make food, like seaweed or pond scum.

For teachers: photosynthetic, eukaryotic organisms that lack true roots, stems, and leaves; the term is often used collectively for the green or brown mass found in water.

- The pond was covered in a thick layer of green algae after the hot summer.
- Excessive nutrient runoff from nearby farms led to a massive bloom of toxic algae, depleting oxygen levels in the lake and killing the fish population.

## Examples

- Green algae grew on the old pond stones.
- The clear lake water allowed sunlight to reach the bottom, helping the algae grow quickly.
- Marine biologists study how rising ocean temperatures affect algae blooms, which can disrupt local ecosystems and oxygen levels.

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