dorsal fin

noun

1. the fin or finlike integumentary expansion generally developed on the back of aquatic vertebrates.

dorsal fin

noun

1. any unpaired median fin on the backs of fishes and some other aquatic vertebrates: maintains balance during locomotion

Word History and Origins

Origin of dorsal fin¹

First recorded in 1760–70

Example Sentences

"A dorsal fin slowly broke the surface revealing that familiar profile that looked like a shark," he said.

From BBC

He thrust the blade into the thick muscle beneath the dorsal fin to attach the tracking device.

From Los Angeles Times

Winter had put a life vest on the dog resembling a shark, with a dorsal fin protruding from its back.

From Los Angeles Times

Yet sea robins are most notable for their distinctively large, fan-shaped dorsal fins and for their six leg-like appendages.

From Salon

The dorsal fin is like a dolphin's fingerprint, as each has distinctive notches, ridges and pigmentation.

From BBC