struggle vs get back

struggle is a noun but get back is not a noun.

Word	Noun	Adjective	Verb	Adverb
struggle	Yes	No	Yes	No
get back	No	No	Yes	No

As verbs, get back is a hyponym of struggle; that is, get back is a word with a more specific, narrower meaning than struggle:

struggle (noun)	get back (noun)
strenuous effort
an energetic attempt to achieve something
an open clash between two opposing groups (or individuals)

struggle (verb)	get back (verb)
be engaged in a fight; carry on a fight	take revenge or even out a score
to exert strenuous effort against opposition	recover something or somebody that appeared to be lost
climb awkwardly, as if by scrambling	get one's revenge for a wrong or an injury
make a strenuous or labored effort