1. 堆肥;混合肥料
Compost is a mixture of decayed plants and vegetable waste which is added to the soil to help plants grow.

2. (在花盆中栽培用的)特制土
Compost is specially treated soil that you buy and use to grow seeds and plants in pots.

3. 把…制成堆肥
To compost things such as unwanted bits of plants means to make them into compost.

1. a mixture of decaying vegetation and manure
used as a fertilizer