noun
A large container in a bathroom that you fill with water so you can wash your body while sitting or lying down.
I filled the bathtub with warm water.
Please clean the bathtub after your shower.
Good to know
In American English, bathtub is the usual word for the container. Bath can mean washing in it.
Common phrases & grammar
fill the bathtub · clean the bathtub · bathtub drain
fill the bathtub with + water
sit in the bathtub