imaginary vs imaginary part

imaginary and imaginary part both are nouns.

Word	Noun	Adjective	Verb	Adverb
imaginary	Yes	Yes	No	No
imaginary part	Yes	No	No	No

imaginary (noun)	imaginary part (noun)
(mathematics) a number of the form a+bi where a and b are real numbers and i is the square root of -1	the part of a complex number that has the square root of -1 as a factor

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