the world > the earth > minerals > mineral deposits > features of stratum or vein > [verb (intransitive)] > slope down (3)
intransitive. To incline or slope from the vertical, as a shaft, or a vein or fault.
intransitive. To incline or slope, esp. downwards; (U.S., of a roof) to dip down. Also Mining and Geology: (of a linear feature) to have a pitch…
Mining. Of a vein: To dip. Obsolete. rare.