bo·​to ˈbō-ˌtü How to pronounce boto (audio)
variants or less commonly bouto
plural botos also boutos
: a large, heavy river dolphin (Inia geoffrensis) native to the Amazon and Orinoco river basins that is dark gray when young and pinkish as an adult
The boto—the largest of the four remaining species of river dolphin—is well adapted to its murky environment. Unfused vertebrae in its neck mean it is capable of turning its head through a range of 180 degrees, allowing it to squeeze around submerged trees and roots.Rowan Hooper, New Scientist, 17 Dec. 2011

called also Amazon dolphin, Amazon river dolphin, pink dolphin, pink river dolphin

Word History


borrowed from Brazilian Portuguese boto, perhaps from regional Portuguese, "wineskin," going back to Late Latin buttis "cask"; from its shape

First Known Use

1875, in the meaning defined above

Time Traveler
The first known use of boto was in 1875

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Dictionary Entries Near boto

Cite this Entry

“Boto.” Dictionary, Merriam-Webster, Accessed 26 Feb. 2024.

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