a small elevator used to convey food (or other goods) from one floor of a building to another
A small elevator used to move food etc. from one floor of a building to another.
The word combines "dumb," meaning unable to speak, with "waiter." Originally describing a portable table that could not gossip, the term later evolved in the 1840s to refer to small service elevators, using "dumb" to mean purely mechanical and silent.