Characterized by or relating to addition; involving the process of adding. The additive nature of the process means that each step builds upon the previous one.
Relating to a substance added to something in small quantities to improve or preserve it. The additive properties of the chemical help to enhance the flavor of the food.
Mathematics & Physics: of a function, quantity, or effect whose value for the whole is equal to the sum of its values for the parts. Entropy is an additive quantity for independent subsystems.