carboniferous vs carbonic

carboniferous and carbonic both are adjectives.

Word	Noun	Adjective	Verb	Adverb
carboniferous	No	Yes	No	No
carbonic	No	Yes	No	No

As adjectives, carboniferous and carbonic are synonyms defined as:

carboniferous and carbonic: relating to or consisting of or yielding carbon

Other synonyms of carboniferous include carbonaceous, carbonous.

carboniferous (adjective)	carbonic (adjective)
relating to or consisting of or yielding carbon	relating to or consisting of or yielding carbon
of or relating to the Carboniferous geologic era