When you're trying to hit on someone in a bar, but in order to make progress you need to cut loose his or her friend (because they are unattractive, annoying, etc.). This can be extremelydifficult if the friend is a woman, as these friends typically don't like to be pushed aside, and will actively try to ruin the night for the potential couple.
"That girl was totally feeling me, but her fat friend was pissed offthat there wasn't a wingman for her, so I had to pull a friendectomy."
Noun.
1. The process of selectively removing persons deemed offensive, disrespectful, or having questionable motives from one's social circle or collection of friends.
2. In social media, e.g. Facebook, MySpace, Google, Twitter, the process of deleting, removing or "unfriending" such persons from one's friends or contact list.
I'm about to perform a Facebook friendectomy because the things she keeps saying on my page are just plain stupid.
The act of cutting out the de-friending of a Facebook friend. In other words, adding someone back after they are removed from the friend list on someone's Facebook page.
Joe was de-friended?? no way! Bob needs to perform a Joe de-friendectomy, i.e. re-friend Joe now!