*Mushin in Japanese: No Mind
*Wuxin in Chinese (無心 "no mind")
*Is a mental state
Zen and Daoist meditators attempt to reach this state, as well as artists, musicians and trained martial artists.
One of my uses of Mushin/Wuxin is to be able to apply this mental state during everyday activities, doing whatever I choose to do.
From Wikipedia:
On page 84 of his 1979 book Zen in the Martial Arts, Joe Hyams claimed Bruce Lee read the following quote to him, attributed to the legendary Zen master Takuan Sōhō:[8]
The mind must always be in the state of 'flowing,' for when it stops anywhere that means the flow is interrupted and it is this interruption that is injurious to the well-being of the mind. In the case of the swordsman, it means death.
When the swordsman stands against his opponent, he is not to think of the opponent, nor of himself, nor of his enemy's sword movements. He just stands there with his sword which, regardless of all technique, is ready only to follow the dictates of the subconscious. The man has effaced himself as the wielder of the sword. When he strikes, it is not the man but the sword in the hand of the man's subconscious that strikes.