IPA: /ˈɛfərtfəl/
KK: /ˈɛfərtfəl/
The quality or state of requiring a lot of physical or mental energy to accomplish something.
The effortfulness of the task made it challenging for the students to complete it on time.
Effortfulness is formed from "effort" (from Old French *esforcier*, meaning to exert oneself) and "-fulness" (meaning the state of being full of). The word describes the quality or state of being full of effort or exertion.
Think of 'effort' as the act of trying hard, and '-fulness' means being full of that quality. So, effortfulness means being full of effort.