What is the term used when water is lost or removed from the body?

The correct term for when water is lost or removed from the body is dehydration. Dehydration occurs when the amount of water in the body falls below the normal level, leading to an imbalance that can affect bodily functions. This can happen due to various reasons such as excessive sweating, diarrhea, vomiting, or not drinking enough fluids.

Dehydration is a significant health issue because water is crucial for maintaining numerous physiological functions, including temperature regulation, nutrient transport, and waste elimination.

Other choices relate to different concepts. Deficiency typically refers to a lack of essential nutrients in the diet, rather than water specifically. Desiccation usually describes the process of drying out something, such as food items, but it is not specifically used in a biological context like dehydration. Evaporation refers to the process of a liquid turning into vapor and is not directly related to the removal of water from the body.