A baby shower is a party held before a baby arrives. Throw a baby shower.
It is American in origin and reached Britain only in the last thirty years. A baby shower is where most of the equipment for a first child actually comes from.
1nounbaby showerA party held before a baby arrives.
“The baby shower produced four identical sets of blankets.”
baby shower is a party.
Baby plus shower, from being showered with gifts, on the model of a bridal shower.
From baby + shower (in the sense of being showered with gifts), perhaps influenced by bridal shower.
Etymology from Wiktionary, CC BY-SA
Practised in Babies & Growing Up