Somersault

A somersault is an acrobatic move where a person moves the feet over the head whilst in mid-air. The somersault can be done forwards, backwards, or sideways and is similar to a flip (or, if performed backwards, a backflip). A backwards somersault while still moving forward is called a Gainer

An animation of a flip in the air

The word comes from the old French word sombresault, which is no longer used.