A single pip is a 100th of a cent move in a market in relation to leverage trading. It is a common term of measurement used in currency trading such as trading markets like EURUSD to AUDUSD.
An example of a pip could be in reference to a 30 pip profit. Buying AUDUSD at a price of 0.66 cents vs the USD and selling that position at 0.6630, this would be a profit of 30 pips.
An example of losing 30 pips, would be buying AUDUSD at 0.6630 and closing that position at 0.66 for a 30 pip loss.