Definition of Altithermal in US English:

Altithermal

adjective

Ecology Archaeology
  • Designating a period of the Holocene, between about 7500 and 5500 years ago, when the western United States was relatively warm; of or relating to this period. Also as noun: this period.

Origin

1940s. From alti- + thermal. Compare Anathermal and Medithermal.

Pronunciation

Altithermal

/ˈaltɪˌθəːml/