Word | Noun | Adjective | Verb | Adverb |
---|---|---|---|---|
geological period | Yes | No | No | No |
Silurian period | Yes | No | No | No |
geological period (noun) | Silurian period (noun) |
---|---|
a unit of geological time during which a system of rocks formed | the period from 425 million to 405 million years ago; characterized by the first air-breathing animals |