Which term describes an overwhelming feeling of exhaustion?

The term that best describes an overwhelming feeling of exhaustion is fatigue. Fatigue encompasses a state of physical and mental weariness that is not relieved by rest and can significantly impact an individual's ability to function effectively. It is often characterized by a lack of energy and motivation, and it can be a symptom of various health conditions or a result of lifestyle factors such as stress, lack of sleep, or overexertion.

While lethargy refers to a lack of energy and enthusiasm, it typically emphasizes a sluggish or inactive state rather than the profound feeling of exhaustion associated with fatigue. Weakness generally refers to a diminished strength, which can occur due to various medical conditions or injuries, but does not solely capture the essence of exhaustion. Sleepiness, on the other hand, denotes a desire or need to sleep, which may not necessarily convey the totality of physical and mental exhaustion like fatigue does. Thus, fatigue is the most accurate term to describe overwhelming exhaustion.