艮 (☶) is one of the 八卦 (Eight Trigrams) from the I Ching. It represents mountain, stillness, and stopping. In feng shui, 艮 corresponds to the northeast direction.
usage
As an adjective (gěn, 3rd tone), 艮 is a northern dialect word meaning tough/chewy/hard to chew, often describing root vegetables. As a trigram name (gèn, 4th tone), it's more literary.