enthusiasm vs gusto

enthusiasm and gusto both are nouns.

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

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

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

enthusiasm (noun)	gusto (noun)
overflowing with eager enjoyment or approval	vigorous and enthusiastic enjoyment
a lively interest
a feeling of excitement