Adjective: mettlesome me-t(u)l-sum
- Showing courage, determination and energy
"The mettlesome youth took on the challenge";
- game [informal], gamy, gamey, gritty, spirited, spunky [informal]
- Having a proud and unbroken spirit
"The mettlesome horse refused to be tamed"
See also: brave, courageous, spirited