pectoral fin

noun

Updated on: 5 Apr 2018

Definition of pectoral fin

: either of the fins of a fish that correspond to the forelimbs of a quadruped

Recent Examples of pectoral fin from the Web

Over and over again, the dolphin pushed a newborn calf, almost certainly her own, away from the observers' boat and against the current with her snout and pectoral fins.

— barbara j. king, Scientific American, "Humans Are Not the Only Creatures Who Mourn," 23 May 2017
Size: 40 to 50 feet Defining trait: Long pectoral fins, acrobatic breaches Humpback whales have been a rare sight in Oregon and Washington, but in recent years the large cetaceans have been straying closer to Pacific Northwest shores.

— OregonLive.com, "13 whales you can see in the Pacific Northwest, and how to identify them," 21 Dec. 2017
Although sharks use their pectoral fins to swim and position themselves over prey, questions were gradually raised about the functions of the shoulder girdle.

— National Geographic, "These Sharks Feed in a Surprising Way," 18 July 2017
Instead, parts of the fish’s pectoral fins have separated through evolution.

— jason bittel, National Geographic, "Watch a Strange 'Walking Fish' That Has Experts Stumped," 2 June 2017
One youngster’s pectoral fin got stuck between a float and the steel rope at the top of the net.

— lina zeldovich, Smithsonian, "What Will It Take to End International Killer Whale Capture?," 24 Mar. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'pectoral fin.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.