wet the baby's head 

To celebrate the birth of a baby with a drink of alcohol or more usually an excuse for a drinking spree.

Congratulations Bill! How about we go out tonight to wet the baby's head?

wet the baby's head by VAKI5 May 7, 2005

wet the baby's head 

The process of celebrating the birth of a baby. Traditionally taking its name from the Christian baptismal rite, during which the head of a baby would be wet with blesed water, the phrase now commonly relates to the consumption of large amounts of alcohol as a celebration of the new arrival.

The actual process of wetting the baby's head is far more fun before the baby is born.

Bloke 1: check out the cans on that barmaid.
Bloke 2: Dude, you're married.
Bloke 1: Yeah, but...
Bloke 2: You're wife just had a kid.
Bloke 1: Yeah, well..
Bloke 2: We're here celebrating, to wet the baby's head.
Bloke 1: True. But she has got really nice cans.

wet the baby's head by Phil Bool September 27, 2006

wet the baby's head 

To have sex with an extremely pregnant woman.

Person 1: I banged my girl yesterday, she's 38 weeks pregnant!
Person 2: You wet the baby's head, huh?

wet the baby's head by TookLongEnough November 3, 2012