oil and water

used to refer to two elements, factors, or people that do not agree or blend together

油和水（指互不相容的因素或人）

oil the wheels

help something go smoothly

帮助事情顺利进行

compliments oil the wheels of life.

称赞会使生活更好过。

oil (someone's) hand 或 oil (someone's) palm 【非正式用语】

To bribe

行贿

an attorney who tried to oil the judge's hand in order to obtain a directed verdict favorable to his client.

为使判决导向有利于其委托人的局面而试着向法官行贿的律师

To give a tip to

给…小费

oiled the headwaiter's palm.

给领班小费