Deficits in pensions accounting
The excess of liabilities over assets in a funded Defined benefit pension scheme; also known as under-funding.
Pension liabilities = 100.
Pension assets = 90.
The deficit would be:
100 - 90
(Not to be confused with the percentage funding level which in this example would be 90 / 100 = 90%.)
Relevant accounting standards include Section 28 of FRS 102.
More generally, a 'deficit' means any financial shortfall.