be all wet—(U.S. coll.) be completely wrong:
- If you think I’m going to take that kind of talk from you, you’re all wet.
be wet—(UK coll.) be unable to make decisions or take firm actions:
- Don’t be so wet! Just tell them that you don’t want to go.
Note: Neither expression correlates in meaning with the phrase be wet behind the ears—(coll.) be young, naive, and inexperienced:
- For a twenty-five-year-old kid, still wet behind his ears, he got a lot of wisdom from somewhere.
Cf.: be dry behind the ears—be mature or experienced:
- The three children, barely dry behind the ears, have taken over running the family dairy.