• bathrob,
• bathtubes,
• bathrubs,
• bathtube,
• bathrub,
• bathub,
• bathtup,
• bathutb,
• vathtub,
• nathtub,
• hathtub,
• bwthtub,
• bathtb,
• batthub,
• bathteb,
• bath tub,
• bathtab,
• bathtabe,
• bachtub,
• barchtub

The adjective form of the word "bathtub" is "bathtubby". However, it is not commonly used. A more common way to refer to something related to a bathtub would be "bathroom" or "bath".

The plural of the "bathtub" can be the "bathtubs".

The singular of the "bathtub" can be the "bathtub".