n.1 the amount by which a thing (esp. a sum of money) is too small.
2 an excess of liabilities over assets in a given period, esp. a financial year (opp. SURPLUS).
Phrases and idioms:
deficit financing financing of (esp. State) spending by borrowing. deficit spending spending, esp. by the State, financed by borrowing.
Etymology: F d{eacute}ficit f. L deficit 3rd sing. pres. of deficere (as DEFECT)