dorsal fin

US /ˈdɔːr.səl ˌfɪn/

UK /ˈdɔːr.səl ˌfɪn/

1.

a fin on the back of a fish or whale

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The shark's dorsal fin cut through the water.

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We spotted a whale's dorsal fin in the distance.

:

fin pectoral fin adipose fin caudal fin pelvic fin