piquancy vs piquantness

piquancy and piquantness both are nouns.

Word	Noun	Adjective	Verb	Adverb
piquancy	Yes	No	No	No
piquantness	Yes	No	No	No

As nouns, piquancy and piquantness are synonyms defined as:

Other synonyms of piquancy include nip, piquance, tang, tanginess, zest.

As nouns, piquancy and piquantness are synonyms defined as:

piquancy and piquantness: the quality of being agreeably stimulating or mentally exciting

Other synonyms of piquancy include piquance.

piquancy (noun)	piquantness (noun)
a tart spicy quality	a tart spicy quality
the quality of being agreeably stimulating or mentally exciting	the quality of being agreeably stimulating or mentally exciting