fourth power vs quartic

fourth power and quartic both are nouns.

Word	Noun	Adjective	Verb	Adverb
fourth power	Yes	No	No	No
quartic	Yes	No	No	No

As nouns, fourth power and quartic are synonyms defined as:

fourth power and quartic: an algebraic equation or function of the fourth degree

Other synonyms of fourth power include biquadrate, biquadratic.

fourth power (noun)	quartic (noun)
an algebraic equation or function of the fourth degree	an algebraic equation or function of the fourth degree