1. 润滑油
    Grease is a thick, oily substance which is put on the moving parts of cars and other machines in order to make them work smoothly.

    e.g. ...grease-stained hands.
           沾满油渍的手

2. 给…加润滑油；为…涂（或抹）油
    If you grease a part of a car, machine, or device, you put grease on it in order to make it work smoothly.

grease

    e.g. I greased front and rear hubs and adjusted the brakes.
           我在前后轮毂上都抹了润滑油，还调校了刹车。

3. （皮肤分泌的）油脂
    Grease is an oily substance that is produced by your skin.

    e.g. His hair is thick with grease.
           他的头发油乎乎的。

4. 动物油脂
    Grease is animal fat that is produced by cooking meat. You can use grease for cooking.

    e.g. He could smell the bacon grease.
           他闻到一股腌肉的油脂味儿。

5. 给…涂上油（以防粘锅）
    If you grease a dish, you put a small amount of fat or oil around the inside of it in order to prevent food sticking to it during cooking.

    e.g. Grease two sturdy baking sheets and heat the oven to 400 degrees...
           在两块结实的烤板上抹些油，把烤炉加热到400度。
    e.g. Place the frozen rolls on a greased baking tray.
           将冷冻的肉卷放到抹了油的烤盘上。

6. see also: elbow grease