The swingout is the defining dance move of Lindy Hop.
[1] The swingout evolved from the breakaway, which in turn evolved from the Texas Tommy.
The first documented mention of the swingout pattern that resembles breakaway was in 1911, to describe a "Texas Tommy Swing" show done at the Fairmont Hotel in San Francisco.
[2] Its variants are used in Jive, East Coast Swing, West Coast Swing and Modern Jive.
[3]