big time vs success

big time and success both are nouns.

Word	Noun	Adjective	Verb	Adverb
big time	Yes	No	No	No
success	Yes	No	No	No

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

big time (noun)	success (noun)
the highest level of an occupation (especially in entertainment)	an attainment that is successful
	an event that accomplishes its intended purpose
	a person with a record of successes
	a state of prosperity or fame