enthusiasm vs zest

enthusiasm and zest both are nouns.

Word	Noun	Adjective	Verb	Adverb
enthusiasm	Yes	No	No	No
zest	Yes	No	Yes	No

As nouns, zest is a hyponym of enthusiasm; that is, zest is a word with a more specific, narrower meaning than enthusiasm:

Other hyponyms of enthusiasm include gusto, relish, zestfulness, avidity, avidness, eagerness, keenness, exuberance, technophilia.

enthusiasm (noun)	zest (noun)
overflowing with eager enjoyment or approval	a tart spicy quality
a lively interest	vigorous and enthusiastic enjoyment
a feeling of excitement

enthusiasm (verb)	zest (verb)
	add herbs or spices to