Water loss from the leaves is called transpiration. 

Most of the water a plant loses is lost due to a natural process called transpirationThe process where plant roots will take up water and then release water vapor through pores (stomata) in the leaves.. Plants have little pores (holes or openings) on the underside of their leaves, called stomataLittle holes in the lower surface of a leaf through which water and gas can move in and out of a plant.. Plants will absorb water through their roots and release water as vapor into the air through these stomata. To survive in drought conditions, plants need to decrease transpiration to limit their water loss.