The character has 山 (mountain) on top of 圭 (jade tablet). Picture a mountain face that drops off like a flat tablet edge — a cliff.
usage
Most commonly seen in 悬崖 (xuányá, cliff/precipice). The idiom 悬崖勒马 (xuányálèmǎ) means 'to rein in the horse at the edge of the cliff' — to pull back from the brink just in time.
