additive的基本意思是“附加物; 添加物; 添加剂; 加成剂”,是可数名词,尤指食品添加剂。

Food additives can cause allergies. 食品添加剂可能引起过敏。
It says on the packet that these crisps contain no additives. 包装上说这些炸马铃薯片不含添加剂。
Colour is often an additive in foods.颜料经常是各种食物中的添加物。
This margarine is full of additives—just look at the label！这种人造奶油充满了添加剂——看看这个标签！

additive用作形容词时不用于比较等级。

用作定语
▲～+n.
This is an additive ingredient.这是一种添加成分。
用作表语
▲S+be+～
The process of cultural development is additive. 文化发展是一个累积的过程。

［派生词］ additively adv. 附加地