Word | Noun | Adjective | Verb | Adverb |
---|---|---|---|---|
geological period | Yes | No | No | No |
Ordovician | Yes | No | No | No |
geological period (noun) | Ordovician (noun) |
---|---|
a unit of geological time during which a system of rocks formed | the period from 500 million to 425 million years ago; characterized by conodonts and ostracods and algae and seaweeds |