1. 使（数目、大小、数量等）保持在低水平；抑制…增长
If you keep the number, size, or amount of something down, you do not let it get bigger or go higher.
2. 压制；压服；镇压
If someone keeps a group of people down, they prevent them from getting power and status and being completely free.
3. 不使（食物或饮料）吐出
If you keep food or drink down, you manage to swallow it properly and not vomit, even though you feel sick.
1. manage not to throw up
2. place a limit on the number of
Synonym: number
3. put down by force or intimidation
e.g. The government quashes any attempt of an uprising
China keeps down her dissidents very efficiently
The rich landowners subjugated the peasants working the land