- 1 [uncountable] a feeling of being extremely tired, usually because of hard work or exercise synonym exhaustion physical and mental fatigue Driver fatigue was to blame for the accident. I was heavy with fatigue and could not keep my eyes open.
- 2 [uncountable] (usually after another noun) a feeling of not wanting to do a particular activity any longer because you have done too much of it battle fatigue compassion fatigue (= the inability to feel pity for other people's suffering any more) brought on by too many fundraisers
- 3[uncountable] weakness in metal or wood caused by repeated bending or stretching The wing of the plane showed signs of metal fatigue.
- 4fatigues [plural] loose clothes worn by soldiers
- 5 (also fatigue detail) [uncountable] duties, such as cleaning and cooking, that soldiers have to do, especially as a punishment We were all put on fatigue detail for a week.