arduousness

This term describes the inherent quality of a task that requires grueling effort, often combining physical exhaustion with mental persistence. It carries a heavier weight than simple difficulty, suggesting a prolonged struggle or a steep, taxing climb toward a goal.

As an abstract noun denoting a quality, it is used almost exclusively in formal or literary registers. In casual conversation, speakers typically prefer the adjective "arduous" or the phrase "how hard it was" rather than employing this nominalized form.