of, denoting, or formed in the fourth period of the Palaeozoic era, between the Silurian and Carboniferous periods, lasting 60-70 million years during which amphibians first appeared
2.
of or relating to Devon
noun
3. the Devonian
Devonian in American English
(dɪˈvoʊniən)
adjective
1.
of Devon, England
2. [sometimesd-]
designating or of the fourth geologic period of the Paleozoic Era, characterized by the development of the first ferns, mosses, gymnosperms, sharks, bony fishes, amphibians, and wingless insects: so called because rocks of the Devonian Period were first studied in Devon, England