real number vs imaginary

real number and imaginary both are nouns.

Word	Noun	Adjective	Verb	Adverb
real number	Yes	No	No	No
imaginary	Yes	Yes	No	No

As nouns, imaginary is a hypernym of real number; that is, imaginary is a word with a broader meaning than real number:

real number: any rational or irrational number
imaginary: (mathematics) a number of the form a+bi where a and b are real numbers and i is the square root of -1

Other hypernyms of real number include complex number, complex quantity, imaginary number.

real number (noun)	imaginary (noun)
any rational or irrational number	(mathematics) a number of the form a+bi where a and b are real numbers and i is the square root of -1

real number (adjective)	imaginary (adjective)
	not based on fact; existing only in the imagination