ordovician | sense examples, Usage and Definition from wordnet dictionary online

Noun ordovician has 1 sense

Ordovician, Ordovician period - from 500 million to 425 million years ago; conodonts and ostracods and algae and seaweeds
--₁ is a kind of period, geological period
--₁ is a part of Paleozoic, Paleozoic era