Meaning

noun a gymnast who performs rolls and somersaults and twists etc.

noun a glass with a flat bottom but no handle or stem; originally had a round bottom

noun a movable obstruction in a lock that must be adjusted to a given position (as by a key) before the bolt can be thrown

originEtymology tree English tumble English -er English tumbler From tumble + -er.

Etymology from Wiktionary, CC BY-SA 3.0