Amazon river dolphin

noun

variants or less commonly Amazon dolphin

: boto

Amazon river dolphins, or botos, have a curious habit: occasionally one will grab some river grass or a rock in its mouth and pop its head above the surface, showing its prize for all to see.

—Henry Fountain, New York Times, 1 Apr. 2008

At up to 450 pounds and eight feet in length, the Amazon dolphin, or boto, is the largest of the four known species of river dolphin.

—Mark Jenkins, National Geographic, June 2009

Word History

First Known Use

1925, in the meaning defined above

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