insensible perspiration [L, in, not, sentire, to feel, per, through, spirare, to breathe] , the loss of body fluid by evaporation, such as normally occurs during respiration. A small amount of perspiration is continually excreted by the sweat glands in the skin. The portion that evaporates before it may be observed also contributes to insensible perspiration. Also called insensible water loss.
