1 a [+ object] : to add air or gas to (something, such as a tire or a balloon) and make it larger
We used a pump to inflate the raft.
inflate [=blow up] a balloon
b [no object] : to become larger by being filled with air or gas
The balloon slowly inflated.
— opposite DEFLATE
2 [+ object]
a : to think or say that (something) is larger or more important than it really is
His memoirs inflate [=exaggerate] his contributions to the war effort.
b : to cause (a person's ego, reputation, etc.) to become too large or great
All the publicity was inflating his ego. [=was making him too proud and conceited]
3 : to increase prices, costs, etc., in a way that is not normal or expected
Economists warn that rapid economic growth could inflate prices.
Increased competition has inflated salaries among professional athletes.
Rapid economic growth may cause prices to inflate.