Is it farther or further?
school of Mahayana Buddhism, 1727, from Japanese, from Chinese ch'an, ultimately from Sanskrit dhyana "thought, meditation," from PIE root *dhya "to see, contemplate."
An approach to religion, arising from Buddhism, that seeks religious enlightenment by meditation in which there is no consciousness of self.
Note: Deliberately irrational statements are sometimes used in Zen to jar persons into realizing the limits of the common uses of the intellect. One well-known example is, “What is the sound of one hand clapping?”