Definition of boto
: 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
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Origin and Etymology of boto
borrowed from Brazilian Portuguese boto, perhaps from regional Portuguese, “wineskin,” going back to Late Latin buttis “cask”; from its shape — more at 7butt
First Known Use: 1875
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