unretirement
/(ˌ)ʌnrɪˈtʌɪəm(ə)nt/originally and chiefly US
noun
The action or fact of returning to work after having retired; an instance of this. Also: a period of time during which a person has returned to work after having retired.
- Frequently with reference to a sportsperson..
Origin
1940s; earliest use found in The Chester Times. From un- + retirement.