/prɪ'zɜ:vətɪv; prɪ`zɝvətɪv/
adj (used for) preserving （用来）保护的, 保存的
*He painted the posts with a preservative liquid. 他在柱子上涂上了起保护作用的液体.
* Salt has a preservative effect on food. 盐对食物有防腐作用.

n [C, U] (type of) substance usedfor preserving 保护剂; 防腐剂
*food free from preservatives不含防腐剂的食品
* Alcohol is used as a preservative in certain foods. 酒精用作某些食物的保护剂.
* Preservative is usually added to tinned meat. 防腐剂通常加在肉类罐头里.

n [U and C]
a chemical substance that is used to prevent things from decaying, for example food or wood
　food that contains no artificial preservatives