na-adjective, noun
dissatisfied with one's assigned role; feeling the role is beneath one
Expresses that the speaker considers the given task or position too insignificant for their abilities. Often used in formal or workplace contexts. Note: This is the original, correct meaning; colloquial misuse as 'not up to the task' is common but considered incorrect.
彼はその仕事は役不足だと感じて、引き受けなかった。
He felt the job was beneath him and didn't accept it.
こんな簡単な作業は私には役不足です。
Such a simple task is not worthy of my abilities.
na-adjective, noun
not up to the task; out of one's depth
Colloquial misuse of 役不足 to mean 'lacking ability for the role'. The correct term for this meaning is 力不足 (ちからぶそく). Despite being widespread, it is often flagged as an error in formal writing.
See also: 力不足 (ちからぶそく)
彼は役不足で、プロジェクトを任せられない。
He's not up to the task, so we can't entrust the project to him.
自分には役不足かもしれないが、頑張ります。
I might be out of my depth, but I'll do my best.