Any plan, concept or idea that is doomed, from the start, to catastrophic failure, usually due to a complete lack of skill and/or knowledge on the part of the planner.
Bob: Hey John, why are you staring at that wall?
John: I was thinking we could knock it down to make this room bigger.
Bob: But what about the floor upstairs? Won't it fall down? That's a load bearing wall...
John: Well, it's not entirely load bearing.
Chip: "Facebook changed again and it sucks!"
Patricia: "Yeah, Facebook's new redesign is NELB."