shortfall vs shortage

shortfall and shortage both are nouns.

Word	Noun	Adjective	Verb	Adverb
shortfall	Yes	No	No	No
shortage	Yes	No	No	No

As nouns, shortfall and shortage are synonyms defined as:

shortfall and shortage: the property of being an amount by which something is less than expected or required

Other synonyms of shortfall include deficit.

shortfall (noun)	shortage (noun)
the property of being an amount by which something is less than expected or required	the property of being an amount by which something is less than expected or required
	an acute insufficiency