Question

What does the idiom to be "a little on the short side" mean?

Answer 1

a bit less than average in height. If the average height for men is 5'8", then someone who is 5'4" could be said to be a little on the short side. Similarly, a man 6'0" might be called a little on the tall side.

A guy 6'8" is a long tall drink of water. But that's a different idiom...

Answer 2

Or when it doesn't come to height, it could mean that you don't have enough. The term could also be used in hockey and golf.