Gerund noun meaning the act or process of releasing air or reducing volume.
Definitions
The act or process of letting air or gas out of something so that it becomes smaller or less inflated. The rapid deflating of the life-raft alarmed the crew.
deflategerund / present participle Used attributively to describe something that causes loss of confidence or value (e.g., "a deflating experience").
Definitions
Causing a loss of confidence, pride, or value; making something or someone feel or appear smaller or less important. It was a deflating moment when the project was rejected.
Allowing air or gas to escape and therefore shrinking or collapsing. They pulled over to fix the deflating tire before it went completely flat.