A person who prevents
everyone around them from discussing the finale of "Lost" because they
haven't watched it
yet. The prefix "Jack" comes from the first name of the candidate Jack Shephard. The suffix "off" refers to the person being a jerk-off.
Co-worker 1: Holy
cow! Did you see "Lost" last night!
Co-worker 2: Shhhhh! This Jack-off dvr'd it last night and watched the ball
game instead. We'll have to talk about it tomorrow.
Co-worker 1: What a jerk-off!
Co-worker 2: You mean Jack-off.
Co-worker 1: Yeah,
whatever.