(a) Transpiration — Transpiration is the loss of water in the form of water vapour from the aerial parts (leaves and stem) of the plant.
(b) Exudation — The process by which plants lose water or other fluids along with dissolved substances directly in liquid form and not as water vapour is called exudation.
(c) Potometer — Potometer is a device that measures the rate of water intake by a plant and this water intake is almost equal to the water lost through transpiration.
(d) Wilting — The drying out, drooping and withering of the leaves of a plant due to inadequate water supply, excessive transpiration, or vascular disease.
(e) Hydathodes — Special pore-bearing structures present on the margins of the leaf to allow exudation are called hydathodes.
(f) Cuticle — Cuticle is a waxy layer secreted by the epidermis on the two surfaces of the leaf which prevents evaporation of water from the leaf surfaces.