nonlinear distortion vs amplitude distortion

nonlinear distortion and amplitude distortion both are nouns.

Word	Noun	Adjective	Verb	Adverb
nonlinear distortion	Yes	No	No	No
amplitude distortion	Yes	No	No	No

As nouns, nonlinear distortion and amplitude distortion are synonyms defined as:

nonlinear distortion and amplitude distortion: distortion that occurs when the output signal does not have a linear relation to the input signal

nonlinear distortion (noun)	amplitude distortion (noun)
distortion that occurs when the output signal does not have a linear relation to the input signal	distortion that occurs when the output signal does not have a linear relation to the input signal