acridity vs acridness

acridity and acridness both are nouns.

Word	Noun	Adjective	Verb	Adverb
acridity	Yes	No	No	No
acridness	Yes	No	No	No

As nouns, acridity and acridness are synonyms defined as:

As nouns, acridity and acridness are synonyms defined as:

acridity and acridness: the quality of being sharply disagreeable in language or tone

acridity (noun)	acridness (noun)
extreme bitterness	extreme bitterness
the quality of being sharply disagreeable in language or tone	the quality of being sharply disagreeable in language or tone
having an acrid smell