noun

• (archaic) One who tumbles; one who plays tricks by various motions of the body.
• 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.
• A rotating device for smoothing and polishing rough objects, placed inside it, on relatively small parts.
• 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 sear point to enter.
• A drinking glass that has no stem, foot, or handle — so called because such glasses originally had a pointed or convex base and could not be set down without spilling. This compelled the drinker to finish their measure.
• A variety of the domestic pigeon remarkable for its habit of tumbling, or turning somersaults, during its flight.
• A beverage cup, typically made of stainless steel, that is broad at the top and narrow at the bottom commonly used in India.
• Something that causes (something else) to tumble.
• (obsolete) A dog of a breed that tumbles when pursuing game, formerly used in hunting rabbits.
• (UK, Scotland, dialect, obsolete) A kind of cart; a tumbril.
• The pupa of a mosquito.
• One of a set of levers from which the heddles hang in some looms.
• (obsolete) A porpoise.
• (cryptocurrencies) A service that mixes potentially identifiable or 'tainted' cryptocurrency funds with others, so as to obscure the audit trail; used for money laundering.