English Reference

Word

plankton

Phoneticsplank·ton

US/ˈpɫæŋktən/

UK/plˈæŋktən/

Definition

n. tiny plants and animals that drift in the ocean or fresh water. They are a very important food source for many larger sea creatures like whales.

n. a diverse collection of organisms that live in large bodies of water and are unable to swim against a current. Provides a crucial foundational role in aquatic food webs and the global carbon cycle.

Examples

“Many whales eat tiny plankton to survive.”

“The health of the local fish population depends heavily on the seasonal availability of plankton in the upper layers of the ocean.”

Examples

simple

“Many whales eat tiny plankton to survive.”

contextual

“The health of the local fish population depends heavily on the seasonal availability of plankton in the upper layers of the ocean.”

Usage

Usually treated as a collective singular noun; occasionally used as a plural in scientific contexts to refer to different species.

Real-World Examples

“Organs hadn’t been invented yet, so “eating” just meant waiting for tiny particles of food, like bits of plankton or bacteria, to float into the only opening in the animal’s body.”
Ars Technica · 12 Aug 2026
“Because that compound is produced on Earth by ocean plankton, it could be a sign of the presence of organic life.”
The Guardian · 11 Aug 2026

Etymology

Borrowed from German Plankton, coined by German zoologist and marine biologist Victor Hensen. By surface analysis, Ancient Greek πλαγκτός (planktós, “drifter”) + -on. Ultimately from Ancient Greek πλαγκτόν (planktón, “drifting”), neuter nominative of πλαγκτός (planktós), from πλάζομαι (plázomai, “to wander, drift”), from πλάζω (plázō, “to cause to wander, drive astray”). By surface analysis, plankt- + -on.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry

Level
C1 · Advanced
Frequency
Occasional
Updated

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English Reference