piquantness vs piquancy

piquantness and piquancy both are nouns.

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

As nouns, piquantness and piquancy are synonyms defined as:

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

As nouns, piquantness and piquancy are synonyms defined as:

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

Other synonyms of piquantness include piquance.

piquantness (noun)	piquancy (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