The size of something is how big or small it is. Something's size is determined by comparing it to other things, counting it, or measuring it.

The size of something is the fact that it is very large.

A size is one of a series of graded measurements, especially for things such as clothes or shoes.

If someone is cut down to size, something happens to make them realize that they are not as important as they think they are.

If an object is cut to size, its size is altered to make it suitable for a particular purpose.

If you try something on for size, you try it to see if it is suitable for you.