Cambrian

adjective

Cam·​bri·​an ˈkam-brē-ən  ˈkām- 

1

: welsh

2

: of, relating to, or being the earliest geologic period of the Paleozoic era or the corresponding system of rocks marked by fossils of nearly every major invertebrate animal group see Geologic Time Table

Cambrian noun

Examples of Cambrian in a Sentence

Recent Examples on the Web

In a study published in July, researchers from the University of Cambridge announced a first-of-its-kind discovery of thousands of microscopic fossils from the Cambrian period unearthed from the Grand Canyon’s walls. —John Leos, AZCentral.com, 1 Aug. 2025

The Cambrian explosion, which occurred more than 500 million years ago, saw animals evolve and diversify quickly. —Sara Hashemi, Smithsonian Magazine, 29 July 2025

Due to exceptional preservation, the Sirius Passet is an archaeological gold mine for marine organisms from the Early Cambrian period (518 million years ago). —Stephanie Edwards, Discover Magazine, 25 July 2025

Scientists still debate what drove the Cambrian explosion, but the most popular theory is that oxygen in the Earth’s atmosphere slowly began to increase about 550 million years ago, said Erik Sperling, an associate professor of Earth and planetary sciences at Stanford University. —Kameryn Griesser, CNN Money, 24 July 2025

Word History

Etymology

Medieval Latin Cambria Wales, from Middle Welsh Cymry Wales, Welshmen

First Known Use

1603, in the meaning defined at sense 1

Rhymes for Cambrian

• precambrian

Kids Definition

Cambrian

adjective

Cam·​bri·​an ˈkam-brē-ən  ˈkām- 

: of, relating to, or being the earliest period of the Paleozoic era of geological history or the corresponding system of rocks marked by fossils of nearly every major invertebrate animal group see geologic time

Cambrian noun