real number vs imaginary number

real number and imaginary number both are nouns.

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

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

real number: any rational or irrational number
imaginary number: (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.

real number (noun)	imaginary number (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