blue whale

American  

[bloo hweyl, weyl] / ˈblu ˈʰweɪl, ˈweɪl /

noun

1. a migratory baleen whale, Balaenoptera musculus, mostly of oceans and seas in the Southern Hemisphere, the largest mammal ever known, growing to a length of 100 feet (30.5 meters) and having a furrowed, slate-blue skin mottled with lighter spots, in some seas acquiring a yellowish coating of diatoms on the underside: now classified as endangered, it was once hunted nearly to extinction, but international conservation efforts begun in the 1960s have enabled the blue whale population to rebound significantly.

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blue whale British  

noun

1. Also called: sulphur-bottom.  the largest mammal: a widely distributed bluish-grey whalebone whale, Sibbaldus (or Balaenoptera ) musculus , closely related and similar to the rorquals: family Balaenopteridae

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Etymology

Origin of blue whale

First recorded in 1850–55

Example Sentences

So can the capital's wildlife compare to the broadcaster's encounters with mountain gorillas in Rwanda, the mimicry of a lyrebird in Australia or a blue whale breaching beside his small boat?

From BBC • Dec. 18, 2025

Jake, nestled into his sleeping bag on a cot underneath the museum's gigantic suspended model of a blue whale, said he was "so happy to be here."

From Barron's • Oct. 25, 2025

The blue whale is usually considered the largest creature in the ocean.

From NewsForKids.net • Nov. 27, 2024

Hunted nearly to extinction during 20th century whaling, the Antarctic blue whale, the world's largest animal, went from a population size of roughly 200,000 to little more than 300.

From Science Daily • Nov. 15, 2024

“If it was a blue whale, Sookie could make contact.”

From "The Line Tender" by Kate Allen