Definitions for "Mastodon"
An extinct genus of mammals closely allied to the elephant, but having less complex molar teeth, and often a pair of lower, as well as upper, tusks, which are incisor teeth. The species were mostly larger than elephants, and their remains occur in nearly all parts of the world in deposits ranging from Miocene to late Quaternary time.
An extinct elephant having a straight back. They were slightly smaller than the Mammoth. Their teeth exhibit a pattern of cone-shaped cusps ideal for browsing. They ate leaves and branches gathered with their trunk from their forest habitat.
Belonging to the same family of the African elephant was bigger and got extincted 12,000 years ago.
Locomotive with 4-10-0 wheel arrangement (refer Whyte)
Mastodon was the unofficial name of the Central Pacific Railroad's number 229, the world's first successful 4-8-0 steam locomotive.
Mastodon is a fictional character in the Marvel Universe, primarily featured in the Wolverine comic books. He first appeared in Wolverine #48 (in a flashback).
Mastodon is a heavy metal band from Atlanta, Georgia. They are usually classified as a heavy metal group, but there have been debates on what specific sub-genre they belong to. There is also a clear hardcore influence on the band, unsurprising as several of its members previously played in hardcore bands.
Keywords:  unusually, large, one
Is one that is unusually large.