success vs first lady

success and first lady both are nouns.

Word	Noun	Adjective	Verb	Adverb
success	Yes	No	No	No
first lady	Yes	No	No	No

As nouns, first lady is a hyponym of success; that is, first lady is a word with a more specific, narrower meaning than success:

Other hyponyms of success include great, highflier, highflyer, natural, sleeper.

success (noun)	first lady (noun)
an attainment that is successful	the wife of a chief executive
an event that accomplishes its intended purpose	the leading woman in an art or profession
a person with a record of successes
a state of prosperity or fame