deficit vs shortfall

deficit and shortfall both are nouns.

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

As nouns, deficit and shortfall are synonyms defined as:

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

Other synonyms of deficit include shortage.

deficit (noun)	shortfall (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 excess of liabilities over assets (usually over a certain period)
(sports) the score by which a team or individual is losing
a deficiency or failure in neurological or mental functioning