Definition of Mesotherium in US English:

Mesotherium

noun

  • A genus of large notoungulates known from fossils of the Pliocene and Pleistocene epochs in South America; a notoungulate of this genus.

Origin

Late 19th century. From scientific Latin Mesotherium, genus name from meso- + -therium.

Pronunciation

Mesotherium

/ˌmɛsə(ʊ)ˈθɪərɪəm/