DHH especially American EnglishAmE a long large container that you fill with water and sit or lie in to wash yourself 浴缸,澡盆SYN British English bath
Examples from the Corpus
bathtub• Science finds that a surfacetension on the water can draw the boats together, like toy boats in a bathtub.• When they arrived, the little boy was lying on the steps leading to a bathtub.• They come fully equipped with beds, furniture, bathtubs and cookingutensils.• He also found five fishswimming in murky water in an old bathtub.• She got it her or she was in the or she was in the bathtub.• I placed you in the bathtub and turned on the water.• Al Capone and bootleggers filled the vacuum: bathtub spirits, peepholes in the door, Joe-sent-me.