1. (geology) Of a geologic period within the Paleozoic era; comprises the Llandovery, Wenlock, Ludlow and Pridoli epochs from about 439 to 409 million years ago.
2. (archaeology) Of or related to the Silures, a pre-Roman British tribe.
1. from 425 million to 405 million years ago; first air-breathing animals
Definition categories: time