deflate

UK: /dɪˈfleɪt/ US: /dɪˈfleɪt/ ,(di flāt′)

Inflections of 'deflate' (v): (⇒ conjugate)

deflates

v 3rd person singular

deflating

v pres p

deflated

v past

deflated

v past p

WordReference Random House Learner's Dictionary of American English © 2025

de•flate /dɪˈfleɪt/   v., -flat•ed, -flat•ing. 

1. [ ~ + obj] to release the air or gas from (something inflated):
   They deflated the tire tubes and changed the outer walls.
2. [no obj] (of something inflated) to have the air or gas be released from:
   The tire quickly deflated when it was punctured by the nail.
3. [ ~ + obj] to lessen or reduce (one's hopes);
   dash:
   The bad news really deflated our hopes for improvement.
4. [ ~ + obj] to reduce (currency or prices) from an inflated condition:
   The economy was badly deflated.

See -flat-.

WordReference Random House Unabridged Dictionary of American English © 2025

de•flate  (di flāt′), v., -flat•ed, -flat•ing. 
v.t. 

1. to release the air or gas from (something inflated, as a balloon):
   They deflated the tires slightly to allow the truck to drive under the overpass.
2. to depress or reduce (a person or a person's ego, hopes, spirits, etc.);
   puncture;
   dash:
   Her rebuff thoroughly deflated me.
3. Economics, Business to reduce (currency, prices, etc.) from an inflated condition;
   to affect with deflation.

v.i. 

4. to become deflated.

• Latin dēflātus blown off, away (past participle of dēflāre), equivalent. to dē- de- + fl(āre) to blow + -ātus -ate¹
• 1890–95

de•fla′tor, n. 

Collins Concise English Dictionary © HarperCollins Publishers::

deflate / dɪˈfleɪt/ verb

1. to collapse or cause to collapse through the release of gas
2. (transitive) to take away the self-esteem or conceit from
3. to cause deflation of (an economy, the money supply, etc)

Etymology: 19th Century: from de- + ( in) flate