ˈbȯ(ə)rd noun
also board ˈbō(ə)rd, ˈbȯ-
( -s )
Etymology: board (I) ; probably from the former practice of laying boards in mine passageways to form a relatively smooth surface along which the coal was dragged in sledges
: a straight road or passageway driven at right angles to the main cleavage of the coal in a coal mine