Real Dictionary

fatigue
uncountable noun: Fatigue is a feeling of extreme physical or mental tiredness.

fatigue in American English
physical or mental exhaustion; weariness
to make or become tired or exhausted; weary
noun: weariness from bodily or mental exertion

fatigue in British English
noun: physical or mental exhaustion due to exertion
verb: to make or become weary or exhausted

fatigue in Mechanical Engineering 1
noun: If a material is subject to fatigue, it gradually cracks as stresses, especially vibrations, are repeatedly applied to it.

fatigue in Mechanical Engineering 2
verb: If something fatigues a material or part, it cracks or breaks it by repeatedly putting stresses on it, or if a material or part fatigues it gradually cracks or breaks.