One who leaches on to your friends through you, distances themselves from you, but still tries to stays friends with all your friends.
I told that bitch never to call me again, but she's still blowing up all my homegirls' cellies, actin like they still tight. I shoulda known that ho was a no good friend jacker.
by K. Clinton May 09, 2008
When a new friend of yours in turn befriends one of your old friends and monopolizes his/her social schedule, effectively locking you out from that old friend.
She's a total friendjacker -- Magnus can't go biking with me because they are rock climbing AGAIN!
by Impunity August 13, 2008
A person who creeps on your social networking page, easing their way through your friends list and sends friend requests to them in the hopes that they will accept the invite due to you being a mutual friend.
My brother Josh is a fucking FriendJacker.......all of a sudden we have 86 mutual friends. What a douche!
by Eli Keller January 02, 2011