yeo·man 
/ˈjoʊmən/ noun
plural yeo·men /ˈjoʊmən/ noun [count] 1 : an officer in the U.S. Navy who works as a clerk 2 : a farmer in the past who owned a small amount of land
yeoman's work/service also yeoman work/service
US : very good, hard, and valuable work that someone does especially to support a cause, to help a team, etc.
▪ They've done yeoman's work in raising money for the organization.
▪ They've done yeoman's work in raising money for the organization.
