Freebase(0.00 / 0 votes)Rate this definition: Exsanguination is the process of blood loss, to a degree sufficient to cause death. One does not have to lose literally all of one's blood to cause death. Depending upon the age, health, and fitness level of the individual, people can die from losing half or two-thirds of their blood; a loss of roughly one-third of the blood volume is considered very serious.