piquancy vs tang

piquancy and tang both are nouns.

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

As nouns, piquancy and tang are synonyms defined as:

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

piquancy (noun)	tang (noun)
a tart spicy quality	any of various kelps especially of the genus Laminaria
the quality of being agreeably stimulating or mentally exciting	any of various coarse seaweeds
	brown algae seaweed with serrated edges
	a common rockweed used in preparing kelp and as manure
	a tart spicy quality
	the taste experience when a savoury condiment is taken into the mouth