purpose vs firmness of purpose

purpose and firmness of purpose both are nouns.

Word	Noun	Adjective	Verb	Adverb
purpose	Yes	No	Yes	No
firmness of purpose	Yes	No	No	No

As nouns, firmness of purpose is a hypernym of purpose; that is, firmness of purpose is a word with a broader meaning than purpose:

purpose: the quality of being determined to do or achieve something; firmness of purpose
firmness of purpose: the trait of being resolute

Other hypernyms of purpose include firmness, resoluteness, resolution, resolve.

purpose (noun)	firmness of purpose (noun)
what something is used for	the trait of being resolute
the quality of being determined to do or achieve something; firmness of purpose
an anticipated outcome that is intended or that guides your planned actions

purpose (verb)	firmness of purpose (verb)
reach a decision
propose or intend