a cause of weariness; slow ordeal; exertion: the fatigue of driving for many hours.
Physiology. temporary diminution of the irritability or functioning of organs, tissues, or cells after excessive exertion or stimulation.
Civil Engineering. the weakening or breakdown of material subjected to stress, especially a repeated series of stresses.
Also called fatigue duty. Military. labor of a generally nonmilitary kind done by soldiers, such as cleaning up an area, digging drainage ditches, or raking leaves. the state of being engaged in such labor: on fatigue.