What is “Pot Odds” in Poker Texas Hold'em?
Pot Odds is a term that describes the ratio of the current bet to the pot.

For example, consider if the pot is $100 and you need to make a $10 bet to stay in.  Your hand is a dog, and you estimate only a 20% chance for you to win.  Pot odds would say that you should make the bet as you are getting 10-1 on your $10.

You can get more information from the Wikipedia entry on Pot Odds.