short ‧ fall /ˈʃɔːtfɔːl $ ˈʃɔːrtfɒːl/ BrE AmE noun [countable]
the difference between the amount you have and the amount you need or expect ⇨ deficit
shortfall in
Parents have been asked to pay £30 each to cover the shortfall in the budget.
shortfall of
an estimated shortfall of about £1 million