tumbleset

tum·ble·set

 (tŭm′bəl-sĕt′)
n. Lower Southern US

[Blend of tumble and somerset (alteration of somersaut, variant of somersault).]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

tumbleset

(ˈtʌmbəlˌsɛt)
n
(Gymnastics) Southern US a somersault
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014