What does "pull up your socks" mean?

The socks that people wear on their feet are not very exciting, but several interesting English expressions are made from them. One such expression is "pull up your socks". It means "try to do better", "improve your performance". Imagine a basketball team near the end of an important game. The players are losing. They are so tired that even their socks look tired. The tops of their socks are falling down over their shoes. The coach calls time Out to talk to his team.  "Take a deep breath," he tells them.  "Get organized.  If you pull up your socks, you can win this game.  "He is telling them they can win if they start playing better. A newspaper once reported that a political leader told members of his party that they needed to pull up their socks and get back in the game.
   Another expression is to "sock some money away". It means to save some money instead of spending it. A friend might tell yon, for example, that she is socking some money away for a holiday trip. Word experts say the expression probably came from people hiding their savings in a sock instead of putting it in a bank.