Aerate: to supply with air. Do you hear that you should do this to your your wine? Why? And to which ones: Red, white, rose?
The Yuppie Chef explains it well; "when wine is bottled, it is secured with an airtight seal in order to remain in the state the winemaker intended. Over time, the tannins break down, creating a smoother, more drinkable wine, which is one reason why older wines are more expensive and prized. Aerating a young wine mimics the ageing process, creating a smooth, delicious wine in just a few minutes."
The Wine Folly also has good tips on how long you should let a wine breathe.