1. To press something downwards with your hand using force. English = push down.
2. To reduce the volume of noise being produced by something. English = turn down.
3. Of a person's mental capacities and skills, to become worse. English = deteriorate. Idiomatic English = go downhill.
4. Of a surface, to measure a small distance from the ground to it, or to be near the ground relative to something else; of a quantity, to be a small amount of something, to be almost empty. English = (be) low.