Definition of: tumbler

(tum′blər) noun
1. A drinking glass without a foot; also, its contents. The base was formerly rounded, so that the glass would not stand upright.
2. One who or that which tumbles; especially, an acrobat or contortionist.
3. One of a breed of domestic pigeons noted for the habit of turning forward somersaults during flight.
4. A greyhound used formerly in coursing.
5. In a lock, a latch that engages a bolt and prevents its being shot in either direction unless the tumbler is raised by the key bit.
6. In a firearm lock, a piece attached to the hammer and receiving the thrust of the mainspring.
7. A tumbling box.
8. Mech. a A piece of metal that projects from a revolving or rocking shaft and communicates motion to another piece. b The rocking frame in a tumble gear.
9. Scot. A light cart.
10. A child's toy, so formed and weighted as to rock at the slightest touch.