Backflow and Backwash

Backflow noun - A flow that returns toward its source.

Backwash and backflow are semantically related in reverse flow topic. In some cases you can use "Backwash" instead a noun "Backflow", when it comes to topics like return flow.

Backwash noun - A condition or occurrence traceable to a cause.

Backflow and backwash are semantically related in wake topic. You can use "Backflow" instead a noun "Backwash", if it concerns topics such as reverse flow, return flow.