Gompertz curve
a function or curve used to describe a pattern of growth that is slow at the beginning and end but rather rapid or steep in the middle, thus forming a shape resembling a leaning letter S. For example, the adoption of a fashion fad may follow a Gompertz curve: Few people purchase the product initially, but there is a subsequent period of highly increased sales that precedes a lessening of interest in the product and ultimately very low sales as the fad dies out. Gompertz curves often are used in survival analysis. Also called Gompertz distribution; Gompertz function. [Benjamin Gompertz (1779–1865), British mathematician]