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). deficit financing financing of (esp. State) spending by borrowing. deficit spending spending, esp. by the State, financed by borrowing.
[ F déficit f. L deficit 3rd sing. pres. of deficere (as DEFECT) ]