tie (sb/sth) down （用绳子）捆住，栓住。限制；束缚；牵制。
英文解释为A person or thing that ties you down restricts your freedom in some way.

【例句】
Tie down anything that might blow away in the storm.
把有可能被风暴吹走的所有东西全部拴住。

We'd agreed from the beginning not to tie each other down.
我们一开始就说好了不会互相束缚。