Noun
kneebar (plural kneebars)
(combat sports) A joint lock where the knee is hyperextended in order to cause pain and/or injury.
For the second time in two weeks, Hannah Cifers is back at it after losing to Mackenzie Dern by first round kneebar on May 30. She is scheduled to fight UFC debutant Mariya Agapova. Source: Internet
Perkins reversed the crossface into his own kneebar on Raju. Source: Internet