Ordovician: Meaning and Definition of
Pronunciation: (ôr"du-vish'un), [key]
— Geol. Geol.
- noting or pertaining to a geologic period of the Paleozoic Era, from 500 million to 425 million years ago, notable for the advent of fish. See table at geologic time.
- the Ordovician Period or System.
- ordovician (Thesaurus)