"Deaf and dumb" or “Deaf and Mute” or “Deaf-Mute” (or even just "dumb", when applied to deaf people who do not speak) is an archaic term that is considered offensive.

Many Deaf people do not use a spoken language, thus they are technically "mute". The word "dumb" has at least an archaic meaning that means "mute". Of course, the word "dumb" also has another more common meaning now that implies stupidity, which is certainly not applicable to most Deaf people.

Deaf-mute is a term which was used historically to identify a person who was either deaf using a sign language or both deaf and could not speak. The term continues to be used to refer to deaf people who cannot speak an oral language or have some degree of speaking ability, but choose not to speak because of the negative or unwanted attention atypical voices sometimes attract. Such people communicate using sign language. Some consider it to be a derogatory term if used outside its historical context; the preferred term today is simply "deaf".

Given the long history of deafness, and the fact that Deaf people have been incorrectly assumed to be mentally deficient just because they do not speak, you can imagine that most Deaf people do not appreciate being called "Deaf and Dumb". Today, anyone using the word "dumb" in such context is .... well ... dumb.

A term used to reference cannabis/marijuana/weed.

Rhyming slang used to describe the Bum