deficit UK /ˈdɛfɪsɪt/US /ˈdɛfəsɪt/ noun2 •Deficiency in amount or quality; a falling short; lack.The crop output this year has been comparatively small, owing to the deficit in rainfall. •A situation wherein, or amount whereby, spending exceeds (e.g. government) revenue.But Wall Street, which has a case of deficit-attention disorder, is no longer focused on a balanced budget. "The bond market only worries about one thing at [a time.] — 1996 formsdeficits