What is kung?

Some articles on kung:

List Of Kung Fu Panda Characters - Video Game Characters - Wu Sisters
... Their first film appearance is in Kung Fu Panda Secrets of the Masters in Master Thundering Rhino, Master Storming Ox, and Master Croc's youth ... In the Kung Fu Panda video game, Po ends up stumbling onto the Wu Sisters' base camp when fleeing with the Dragon Scroll ... In Kung Fu Panda Legendary Warriors, the Wu Sisters return amongst the villains that Tai Lung assembles and attack the good guys while Tai Lung was targeting Master Crane ...