Bathtub dream meaning is explained below using 3 different sources. Each interpretation is shown with its source.

Interpretation 1 — Dr. Mıchael Lennox

The bathtub is used for relaxation as much as for cleansing the body. In this way, it can symbolically connect to either, depending on your personal associations with it. From a structural standpoint, because a bathtub contains a small amount of water, it is also an emotional symbol and should be considered from the perspective of containing small amounts of emotional expression that can either relax you or overwhelm you, depending on the dream context.
Source: Complete Dictionary of Dreams Author: Dr. Mıchael Lennox

Interpretation 2 — Dream Explanations - Anonymous

Dreams of a bathtub symbolize a womb and that you are feeling contained as you are cleansed in a healing environment.

See Water.

Source: Strangest Dream Explanations Author: Dream Explanations - Anonymous

Interpretation 3 — myjellybean

To see a bathtub in your dream symbolizes good health and getting over sickness. Also see “Bath” above.
Source: My Dream Interpretation Author: myjellybean