The term 'AREAL' is an adjective that describes the measurement of a surface AREA. It is derived from the Latin word 'AREA', which means 'open space'. This term is used to describe the size of a two-dimensional surface, such as a flat plane or a curved surface. It is usually measured in square units, such as square meters or square feet. AREAL is often used in mathematics, engineering, and geography to measure the size of a surface.