faintness vs dimness

faintness and dimness both are nouns.

Word	Noun	Adjective	Verb	Adverb
faintness	Yes	No	No	No
dimness	Yes	No	No	No

As nouns, faintness and dimness are synonyms defined as:

faintness (noun)	dimness (noun)
the quality of being dim or lacking contrast	the property of lights or sounds that lack brilliance or are reduced in intensity
barely audible	the quality of being dim or lacking contrast
the property of being without strength	the state of being poorly illuminated
the trait of lacking boldness and courage
a feeling of faintness and of being ready to swoon