[ad.di.tive] adj (1699) 1: of, relating to, or characterized by addition
2: produced by addition
3: characterized by, being, or producing effects (as drug responses or gene products) that when the causative factors act together are the sum of their individual effects -- ad.di.tive.ly adv -- ad.di.tiv.i.ty n
[2]additive n (1945): a substance added to another in relatively small amounts to effect a desired change in properties "food ~s"