(informal)appear gentle or innocent while typically being the opposite(非正式)假装天真无邪（或极娴静）；表面上一副老实样
butter someone up
(informal)flatter or otherwise ingratiate oneself with someone(非正式)奉承某人，巴结某人
英语四级真题
In the back room of the little bakery, his interest in design and his baking talent combined to work wonders—he shaped delicious masterpieces out of flour, butter and sugar.
2018年12月四级真题（第二套）阅读 Section B
英语六级真题
Maple Hill signs a contract pledging to buy the farmer's milk at a guaranteed base price, plus quality premiums and incentives for higher protein, butter fat and other solids.
2019年12月六级真题（第三套）阅读 Section B
柯林斯高阶英汉双解学习词典释义
N-MASS
黄油；牛油
Butter is a soft yellow substance made from cream. You spread it on bread or use it in cooking.
If you say that someone knows what side their bread is buttered on, you mean that they know what to do or who to please in order to stay in a good situation or to avoid a bad one.