n. 1. Physical or mental weariness resulting from effort or activity. 2. Something, such as tiring effort or activity, that causes tiredness or weariness: the fatigue of a long hike. 3. Physiology The decreased capacity or complete inability of an organism, organ, or part to function normally because of excessive stimulation or prolonged exertion. 4.
blood - the fluid (red in vertebrates) that is pumped through the body by the heart and contains plasma, blood cells, and platelets; blood carries oxygen and nutrients to the tissues and carries away waste products; the ancients believed that blood was the seat of the emotions
hemo- or hemato-. A prefix meaning blood, as in hemophilia, a disorder in which blood fails to clot, or hematology, the scientific study of blood.