From WordNet (r) 3.0 (2006):
tumble
n 1: an acrobatic feat of rolling or turning end over end
2: a sudden drop from an upright position; "he had a nasty spill
on the ice" [syn: spill, tumble, fall]
v 1: fall down, as if collapsing; "The tower of the World Trade
Center tumbled after the plane hit it" [syn: tumble,
topple]
2: cause to topple or tumble by pushing [syn: topple,
tumble, tip]
3: roll over and over, back and forth
4: fly around; "The clothes tumbled in the dryer"; "rising smoke
whirled in the air" [syn: whirl, tumble, whirl around]
5: fall apart; "the building crumbled after the explosion";
"Negotiations broke down" [syn: crumble, crumple,
tumble, break down, collapse]
6: throw together in a confused mass; "They tumbled the teams
with no apparent pattern"
7: understand, usually after some initial difficulty; "She
didn't know what her classmates were plotting but finally
caught on" [syn: catch on, get wise, get onto,
tumble, latch on, cotton on, twig, get it]
8: fall suddenly and sharply; "Prices tumbled after the
devaluation of the currency"
9: put clothes in a tumbling barrel, where they are whirled
about in hot air, usually with the purpose of drying; "Wash
in warm water and tumble dry"
10: suffer a sudden downfall, overthrow, or defeat
11: do gymnastics, roll and turn skillfully