a dangerous lack of water in the body resulting from inadequate intake of fluids or excessive loss through sweating, vomiting or diarrhoea
"…an estimated 60–70 per cent of diarrhoeal deaths are caused by dehydration"[Indian Journal of Medical Sciences]
COMMENT Water is more essential than food for a human being’s survival. If someone drinks during the day less liquid than is passed out of the body in urine and sweat, he or she begins to dehydrate.