/ ˈtʌmblə(r); NAmE / noun
1.
a glass for drinking out of, with a flat bottom, straight sides and no handle or stem
2.
(also tum·bler·ful / -fʊl; NAmE /) the amount held by a tumbler
3.
( old-fashioned ) an acrobat who performs somersaults (= a jump in which you turn over completely in the air)