fin

Meanings

1. 1nouncountablebiology

   A thin, flat part sticking out from the body of a fish or other water animal, used for steering and swimming.

   Grammar: Often plural for pairs or sets: the fish waved its fins.

   Patterns

   • the fin of something

   The shark's fin sliced through the surface of the water.

   A goldfish uses its tail fin to push forward.

   Scientists studied the shape of each dolphin's dorsal fin to tell the animals apart.

2. 2nouncountabletechnical

   A flat, upright part on something like a surfboard, rocket or aircraft that keeps it steady in motion.

   Grammar: Usually named with a position: tail fin, rear fin.

   Patterns

   • a fin on something

   He replaced the broken fin on his surfboard before the competition.

   The rocket has four fins at its base to keep it flying straight.

   Old American cars were famous for their tall tail fins.

3. 3nounusually pluralAmerican

   A flat rubber blade worn on a foot to help a swimmer or diver move faster.

   Grammar: Normally used in pairs: she put on her fins.

   Patterns

   • a pair of fins

   She strapped on her fins and slid into the lagoon.

   Snorkelers kick gently when wearing fins.

   He packed a mask, a snorkel and a pair of fins.

Word forms

Common combinations

dorsal fin

The dorsal fin of the whale rose above the waves.

tail fin

The fish flicked its tail fin and vanished.

shark fin

A shark fin circled the boat.

pectoral fin

The ray flapped its large pectoral fins like wings.

flap a fin

The tiny fish flapped a fin to stay in place in the current.

Synonyms and how they differ

flipper

A flipper is a broad limb of a seal, turtle or penguin, but a fin on a fish is usually thinner and supported by spines.

vane

A vane is a flat blade that turns or steers in the wind, while a fin is a fixed stabilizing part.

stabilizer

Stabilizer names the job of a part on a ship or plane, whereas fin names its shape.

Word family

finned adjective

having fins

finny adjective

relating to or like a fish, mainly old or poetic

finless adjective

without fins

fin-like adjective

shaped like a fin

Commonly confused: fin or flipper?

Practice

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