be all wet
1. Literally, to be soaked by water. I'm all wet because I got caught in that thunderstorm without an umbrella. The dryer must be broken because my clothes are all wet.
2. To be totally wrong. We need to come up with a new ad campaign because, based on these negative reactions, the old one was all wet.
all wet, to be
To be completely mistaken. The expression is American slang that became current in the first half of the twentieth century. It is not known what wet refers to—soaked from a rainstorm or dunking, drunk and therefore incapable of good judgment, or something else.