A list of friends on the computer. Only limited to 200 friends, you can stalk people as you please.
That slut from school who likes my boyfriend is on my buddy list.
On AIM, Yahoo Messenger, MSN Messenger, etc. a buddy list is list of other instant messenger users that allows you to view thier status (available, idle, away, or disconnected), thier profile (AIM only) and IM them more easily.
Am I on your buddy list?