era vs geologic time

era and geologic time both are nouns.

Word	Noun	Adjective	Verb	Adverb
era	Yes	No	No	No
geologic time	Yes	No	No	No

As nouns, geologic time is a hypernym of era; that is, geologic time is a word with a broader meaning than era:

era: a major division of geological time; an era is usually divided into two or more periods
geologic time: the time of the physical formation and development of the earth (especially prior to human history)

Other hypernyms of era include geological time.

era (noun)	geologic time (noun)
a period marked by distinctive character or reckoned from a fixed point or event	the time of the physical formation and development of the earth (especially prior to human history)
a major division of geological time; an era is usually divided into two or more periods