Definition of Cretaceous in US English:

Cretaceous

adjective

Geology
  • 1Relating to or denoting the last period of the Mesozoic era, between the Jurassic and Tertiary periods.

    The Cretaceous lasted from about 146 million to 65 million years ago. The climate was warm, and the sea level rose; the period is characterized especially in northwestern Europe and parts of North America by the deposition of chalk. The first flowering plants emerged, and the domination of the dinosaurs continued although they died out quite abruptly toward the end of it

    • ‘The Jurassic and Cretaceous together were the age of giant reptiles.’
    • ‘For that matter, extant birds are quite different from Jurassic and Cretaceous birds.’
    • ‘These crucial means of breeding prevailed throughout the Jurassic and Cretaceous times.’
    • ‘The foothills of the Pyrenees are composed of sedimentary Jurassic and Cretaceous limestones which favour the creation of natural cave systems.’
    • ‘As such, they have been found fossilized in Jurassic and Cretaceous deposits, and have been used to reconstruct paleoclimates.’
    1. 1.1as noun the Cretaceous The Cretaceous period or the system of rocks deposited during it.

Origin

Late 17th century: from Latin cretaceus (from creta ‘chalk’) + -ous.

Pronunciation

Cretaceous

/krəˈtāSHəs//krəˈteɪʃəs/