fatigue ,n.[Fr.fatigue. from fa`iguer;L.fatigare.to weary,fatigue]1,weariness;physical or mental exhaustion.2,the cause of weariness;labor;toil;as the fatigues of war. 3,fatigue duty;as;a partyof men on fatigue.4,{pl}fatigue clothes.5,in menchanics ,a weakening in mental ,wood etc.cause by repeated or continued vibrations and strains.6,in physiology ,the decreased ability of an organism or one of its party to function because of prolonged exertion,which causes a toxic decomposition in the muscle and nerve cells.