A unit of heredity. May be defined in different ways for different purposes. Molecular biologists usually emply it in the sense of cistron, I sometimes use it in a more abstract sense. I sometimes use the term gene to mean 'that which segregates and recombines with appreciable frequency', and as 'any hereditary information for which there is a favourable or unfavourable selection bias equal to several or many times its rate of endogenous change'.
