Dictionary.net

a native or resident of Wales

from 544 million to about 500 million years ago; marine invertebrates

a native or resident of Wales

The Cambrian formation.

Of or pertaining to the lowest subdivision of the rocks of the Silurian or Molluscan age; - sometimes described as inferior to the Silurian. It is named from its development in Cambria or Wales. See the Diagram under Geology.

Of or pertaining to the lowest subdivision of the rocks of the Silurian or Molluscan age; - sometimes described as inferior to the Silurian. It is named from its development in Cambria or Wales. See the Diagram under Geology.

The earliest division of the Palaeozoic era.