wet

all wet mistaken; completely wrong. North American

get your feet wet: seefoot.

wet the baby's head celebrate a baby's birth with a drink, usually an alcoholic one. British informal

wet behind the ears lacking experience; immature. informal

☞ The image is of a baby or young animal which is still damp after it has been born.

a wet blanket someone who has a depressing or discouraging effect on others.

☞ A dampened blanket can be used to smother a fire; the image here is of a person extinguishing a lively or optimistic mood by their gloominess or negativity.

2012Guardian How does an actor known for her versatility … embody the grown-up girlfriend who gets in between the boy and his bear without seeming like the wet blanket who's spoiling the party.

wet your whistle have a drink. informal