fin

A flat body part that helps a fish or other sea animal swim and keep its balance.

• The fish has a red fin.
• A shark’s fin appeared above the water.
• These fish use their fins to change direction.

Common phrases: dorsal fin, tail fin, shark fin, dolphin fin

A long, flat piece of rubber worn on the foot to help you swim faster.

• One fin slipped off my foot.
• The divers put on their fins.
• Do these fins help you swim faster?

Similar words: flipper

Common phrases: swimming fin, diving fin, wear a fin

To swim by moving your legs like a fish's tail, often wearing swimming equipment on your feet.

• The diver began to fin slowly.
• We finned toward the reef.
• Try to fin gently without disturbing the sand.

Common phrases: fin gently, fin through water, fin toward something