Meaning of HORSE in English
( n. )
A mass of earthy matter, or rock of the same character as the wall rock, occurring in the course of a vein, as of coal or ore; hence, to take horse -- said of a vein -- is to divide into branches for a distance.
Webster's Revised Unabridged English Dictionary. Пересмотренный полный словарь английского языка Webster. 2012