de·flate / diˈflāt/ • v. 1. [tr.] let air or gas out of (a tire, balloon, or similar object). ∎ [intr.] be emptied of air or gas.2. cause (someone) to suddenly lose confidence or feel less important: [as adj.] (deflated) the news left him feeling utterly deflated. ∎ reduce the level of (an emotion or feeling): her anger was deflated.3. Econ. bring about a general reduction of price levels in (an economy).DERIVATIVES: de·fla·tor / -tər/ n.