fizzle out vs discontinue

fizzle out and discontinue both are verbs.

Word	Noun	Adjective	Verb	Adverb
fizzle out	No	No	Yes	No
discontinue	No	No	Yes	No

As verbs, discontinue is a hypernym of fizzle out; that is, discontinue is a word with a broader meaning than fizzle out:

fizzle out (verb)	discontinue (verb)
end weakly	prevent completion
	put an end to a state or an activity
	come to or be at an end