In 1945, Earl Tupper produced his first polyethylene plastic seven-ounce bathroom tumbler, so called because it could fall or tumble without breaking.
But a “tumbler” drinking glass had already been around for centuries before Tupperware.
It was specially designed with a round or pointed bottom so that it couldn’t stand upright and had to be drunk dry before it could be laid on its side, otherwise it would tumble and spill.
That’s why drinking glasses are sometimes called “tumblers”.
