times vs Roman times

times and Roman times both are nouns.

Word	Noun	Adjective	Verb	Adverb
times	Yes	No	No	No
Roman times	Yes	No	No	No

As nouns, Roman times is a hyponym of times; that is, Roman times is a word with a more specific, narrower meaning than times:

Other hyponyms of times include contemporary world, modern times, modern world, present times.

times (noun)	Roman times (noun)
an arithmetic operation that is the inverse of division; the product of two numbers is computed	the time period during which Rome dominated Europe
a more or less definite period of time now or previously present