Per unit is a term used to describe the cost of a product or service when it is divided by the number of units purchased. It is often used to compare the cost of different products or services. The term can be broken down into three parts: APIECE (6 letters), EACH (4 letters), and APOP (4 letters). APIECE stands for 'amount per item, ' EACH stands for 'EACH, ' and APOP stands for 'amount per one piece.' Together, these three terms form the phrase 'per unit, ' which is used to describe the cost of a product or service when it is divided by the number of units purchased.