can't see a hole in a ladder
1. Is stupid or dimwitted. Don't give Randy that important project—he can't see a hole in a ladder!
2. Is drunk. Don't buy him any more drinks—he already can't see a hole in a ladder.
can't see a hole in a ladder
stupid or drunk. No use asking her questions. She can't see a hole in a ladder. After the big party, Joe needed someone to drive him home. He couldn't see a hole in a ladder.