mammoth (n.)

"large, extinct species of shaggy elephant living in northern latitudes," 1706, from Russian mammot', probably from Ostyak, a Finno-Ugric language of northern Russia (compare Finnish maa "earth"). Because the remains were dug from the earth, the animal was believed to root like a mole.

As an adjective, "gigantic," it is attested from 1802; in this sense "the word appears to be originally American" [Thornton, "American Glossary"], and its first uses are in derogatory accounts of the cheese wheel, more than 4 feet in diameter, sent to President Jefferson by the ladies of the Baptist congregation in Cheshire, Massachusetts, as a present, engraved with the motto "Rebellion to tyrants is obedience to God." Federalist editors mocked the affair, and called up the word mammoth (known from Peale's exhibition) to characterize it.

updated on November 12, 2018

Definitions of mammoth from WordNet
mammoth (n.)
any of numerous extinct elephants widely distributed in the Pleistocene; extremely large with hairy coats and long upcurved tusks;
mammoth (adj.)
so exceedingly large or extensive as to suggest a giant or mammoth;
a mammoth ship
a mammoth multinational corporation
Synonyms: gigantic
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