tossup vs fortune

tossup and fortune both are nouns.

Word	Noun	Adjective	Verb	Adverb
tossup	Yes	No	No	No
fortune	Yes	No	No	No

As nouns, fortune is a hypernym of tossup; that is, fortune is a word with a broader meaning than tossup:

tossup: an unpredictable phenomenon
fortune: an unknown and unpredictable phenomenon that causes an event to result one way rather than another

Other hypernyms of tossup include chance, hazard, luck.

tossup (noun)	fortune (noun)
an unpredictable phenomenon	an unknown and unpredictable phenomenon that causes an event to result one way rather than another
	an unknown and unpredictable phenomenon that leads to a favorable outcome
	a large amount of wealth or prosperity
	your overall circumstances or condition in life (including everything that happens to you)