The term 'POOL Circuit' is a combination of two words, 'LAP' and 'POOL'. LAP is a three-letter word which refers to a swimming stroke in which the swimmer moves forward in a circle. POOL is a four-letter word which refers to a body of water, usually artificially constructed, used for swimming or other water activities. Together, the two words form the term 'POOL Circuit', which is a type of swimming exercise that involves swimming laps in a POOL. This type of exercise is beneficial for improving cardiovascular health and endurance.