noun
small single-person bathtub
Typically a round, deep tub for one person, found in bathhouses or hot springs.
旅館の露天風呂に、小さなつぼ湯があった。
At the inn's open-air bath, there was a small single-person tub.
つぼ湯は一人でゆっくり浸かれるので人気だ。
Single-person tubs are popular because you can soak alone and relax.
Compound of つぼ (tsubo, 'jar' or 'pot') and 湯 (yu, 'hot water'), referring to a small, deep bathtub resembling a pot.