contend vs fight back

contend and fight back both are verbs.

Word	Noun	Adjective	Verb	Adverb
contend	No	No	Yes	No
fight back	No	No	Yes	No

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

contend (verb)	fight back (verb)
to make the subject of dispute, contention, or litigation	fight against or resist strongly
have an argument about something	defend oneself
maintain or assert
compete for something; engage in a contest; measure oneself against others
be engaged in a fight; carry on a fight
succeed in doing, achieving, or producing (something) with the limited or inadequate means available