tumbler

/ˈtʌmbələr/
noun
  1. A flat-bottomed drinking glass with no handle or stem, typically used for water or juice.
    • He dropped his tumbler on the kitchen floor, but it didn't break.
    • The bartender set a tumbler of ice on the counter before adding the soda.
    • She poured herself a glass of water from the pitcher into a clean tumbler.
  2. A person who performs acrobatic feats, such as somersaults and handsprings; an acrobat or gymnast.
    • She trained as a tumbler for years before joining the national gymnastics team.
    • A group of young tumblers practiced their routines on the mats at the park.
    • The circus tumblers amazed the crowd with their flips and cartwheels.
  3. A part of a lock that must be moved to a particular position by a key in order to release the bolt.
    • The locksmith replaced a broken tumbler in the old door lock.
    • When you insert the key, the tumblers align and the lock opens smoothly.
    • Each key is cut to lift the tumblers inside the lock to the correct height.