When you have any two things that are supposed to join together as one to perform a certain function and they don't fit together the correct way they are whompy-jawed.
If you are using a pair of scissors and they don't cut correctly and the blades shift and won't meet like they are supposed to then they are whompy-jawed.
The railing was all wompajawed.
Note: I heard this word from a Colorado native who also uses the word caddywumpus (misaligned, crooked). Come to think of it, they may be synonyms.