Word | Noun | Adjective | Verb | Adverb |
---|---|---|---|---|
geological period | Yes | No | No | No |
Cambrian period | Yes | No | No | No |
geological period (noun) | Cambrian period (noun) |
---|---|
a unit of geological time during which a system of rocks formed | the period from 544 million to about 500 million years ago; characterized by marine invertebrates |