Fatigue or tiredness is a physical or mental feeling. It happens when someone is ready to sleep or has done a lot of physical exercise. The person may feel weak, slow or sleepy. They may yawn, and may find it difficult to keep the eyes open. Usual fatigue goes away when you rest or sleep.
Images for kids
Minor dark circles, in addition to a hint of eye bags, a combination which is suggestive of sleep deprivation and/or mental fatigue.
Fatigue Facts for Kids. Kiddle Encyclopedia.