Tumbersault 

A running dive into a summersault, or forward roll. May also be completed rolling sideways on ones back.

The boy was seen doing a tumbersault in the middle of the road to escape the police.

Tumbersault by ioinfodinfd February 28, 2010

tumblesault 

An inadvertent somersault done with mistaken grace. Usually performed by small animals or someone who is drunk.

My dog just did the craziest tumblesault.

tumblesault by Bippydoodle August 10, 2016

tumbersaulting 

A confusing and dizzying combination of tumbling and somersaulting while one is in mid air, usually a result of a botched high dive.

"Those guys look ridiculous, tumbersaulting through the air like that"

tumbersaulting by steve8311 May 26, 2009

Tumersault 

The feeling in the pit of your stomach when on a roller coaster or drop ride.

That roller coaster was crazy, my stomach was doing mad tumersaults!

Tumersault by Thinkers February 2, 2019