From dumb (“unable to speak”) + waiter, originally separate words and describing the portable table's inability to relate gossip after the meal. By the use of the term to describe small service elevators in American homes in the 1840s, it simply meant dumb as "mechanical", "unable to speak at all".
dumbwaiter (plural dumbwaiters)
- A small elevator used to move food etc. from one floor of a building to another.
- (obsolete) a table or set of trays on rollers used for serving food
- (obsolete) a lazy Susan