pectoral fin

Meaning

1. 1nouncountablebiology

   One of the pair of fins on each side of a fish's body behind the head, used for steering, braking and keeping balance.

   Grammar: Usually plural, since fish have two: the shark's pectoral fins.

   Patterns

   • the pectoral fins of a fish

   The ray flapped its enormous pectoral fins like wings.

   A fish uses its pectoral fins to slow down and turn.

   Biologists noted that the lungfish has thin, whip-like pectoral fins.

Word forms

Common combinations

pair of pectoral fins

Each shark has a pair of pectoral fins.

flap its pectoral fins

The fish flapped its pectoral fins to hover.

pectoral fin ray

A broken pectoral fin ray healed slowly.

large pectoral fins

Flying fish have large pectoral fins for gliding.

pectoral fin and pelvic fin

The pectoral fin and pelvic fin work together to keep the fish level.

Synonyms and how they differ

fin

Fin is the general word for any fish fin, while pectoral fin names the specific pair near the head.

flipper

Flipper is for the broad limbs of seals, whales and penguins, not for fish.

forelimb

Forelimb is the evolutionary counterpart, used for land animals, as the pectoral fin of fish is the ancestor of the arm.

Word family

pectoral adjective

relating to the chest or breast area

pelvic fin noun

the paired fin further back on the belly

dorsal fin noun

the fin on the back

pectorals noun

the chest muscles, informally pecs

Commonly confused: pectoral fin or pelvic fin? pectoral fin or dorsal fin?

Practice

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