to not take action on something until a later time

I've had to shelve my plans to buy a new car, because I can't afford it at the moment. 我不得不推迟买新车的计划，因为目前我还买不起。

to put something onto shelves, or to fix shelves somewhere

When a surface such as the bottom of the sea shelves, it slopes down gradually.

The sea bed shelves gently for several hundred metres. 海床在几百米内逐渐倾斜。