ˈdɛfɪsɪt ˈdɛfəsɪt the property of being an amount by which something is less than expected or required new blood vessels bud out from the already dilated vascular bed to make up the nutritional deficit an excess of liabilities over assets (usually over a certain period) last year there was a serious budgetary deficit (sports) the score by which a team or individual is losing a deficiency or failure in neurological or mental functioning the people concerned have a deficit in verbal memory they have serious linguistic deficits