first lady vs achiever

first lady and achiever both are nouns.

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

As nouns, achiever is a hypernym of first lady; that is, achiever is a word with a broader meaning than first lady:

Other hypernyms of first lady include succeeder, success, winner.

first lady (noun)	achiever (noun)
the wife of a chief executive	a person with a record of successes
the leading woman in an art or profession