IPA: /ˈmɛtəlˌsʌm/
KK: /ˈmɛtəlˌsʌm/
Having a lot of spirit, courage, or determination; brave and lively.
The mettlesome horse jumped over the high fence with ease.
Mettlesome → It is formed from "mettle" (from Middle English *mettel*, meaning spirit or courage) and the suffix "-some" (meaning characterized by). The word "mettlesome" describes someone characterized by spirit or courage.
Think of 'mettle' as representing spirit or courage, and remember that 'mettlesome' means someone who is full of that spirit.