Where does “Devonian” come from?

Devonian derives from English Devon, which comes from Latin -ianus, from Latin -ius, from Latin -um, from Latin -us, from Proto-Indo-European -yós, from Proto-Italic -os, from Proto-Indo-European -ós.

Devonian (English): of a geologic period within the Paleozoic era;...

Definitions

of a geologic period within the Paleozoic era;...

Ancestry of “Devonian”, step by step

Step	Language	Word	Meaning
1	English	-án	Of or pertaining to;. Often added to words of Latin origin, but also used with words of other origins. When a word ends in a
2	Middle English	-an	—

Every word from Middle English -an →Every word from English -án →