Can someone please explain the meaning of 'shorting' a stock with an example?
This is a gross simplification as there are a few different ways to do this. The principle overall is the same though.
To short a stock, you borrow X shares from a third party and sell them at the current price. You now owe the lender X shares but have the proceeds from the sale. If the share price falls you can buy back those shares at the new lower price, return them to the lender and pocket the difference.
The risk comes when the share price goes the other way, you now owe the lender the new value of the shares, so have to find some way to cover the difference. This happened a while back when Porsche made a fortune buying shares in Volkswagen from short sellers, and the price unexpectedly rose.
Rich's answer captures the basic essence of short selling with example.
I'd like to add these additional points: