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

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

tumblesalt

The tumblesalt is an acrobatic feat in which a person tucks in mid-air and moves the feet over the head. The tumblesalt can be performed either forwards, backwards, or sideways and is similar to a flip (or, if performed backwards, backflip).

Jane performed a perfect tumblesalt to win the competition.

tumblesalt by Bob bergousicious January 2, 2008

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