1.
bathtub
The tub portion of a Japanese bath that holds hot water for soaking. In Japanese bathing culture, one washes and rinses outside the tub before entering the bathtub to soak.
Usage
The standard everyday word for a bathtub in Japanese. In Japanese homes, the 湯船 is strictly for soaking, not for washing — one rinses off at a separate washing area before entering. The word literally means "hot water vessel" (from 湯 + 船).
Also called 浴槽, which is more formal/technical.