(1) Relating to or consisting of or yielding carbon
(2) Of or relating to the Carboniferous geologic era
"Carboniferous rock system"
noun
(3) From 345 million to 280 million years ago
WiktionaryText
Adjective
of a geologic period within the Paleozoicera; comprises the lower, middle and upper Mississippian and lower, middle and upper Pennsylvanianepochs from about 345 to 280 million years ago, when coal was laid down
