Webster's Revised Unabridged Dictionary · 1913

Tumbler

Tumbler , noun

1.
One who tumbles; one who plays tricks by various motions of the body; an acrobat.
2.
A movable obstruction in a lock, consisting of a lever, latch, wheel, slide, or the like, which must be adjusted to a particular position by a key or other means before the bolt can be thrown in locking or unlocking.
3.
(Firearms) A piece attached to, or forming part of, the hammer of a gunlock, upon which the mainspring acts and in which are the notches for the sear point to enter.
4.
A drinking glass, without a foot or stem; -- so called because originally it had a pointed or convex base, and could not be set down with any liquor in it, thus compelling the drinker to finish his measure.
5.
(Zoology) A variety of the domestic pigeon remarkable for its habit of tumbling, or turning somersaults, during its flight.
6.
(Zoology) A breed of dogs that tumble when pursuing game. They were formerly used in hunting rabbits.
7.
A kind of cart; a tumbrel. [Provincial English & Scottish]