premise: to <mask> sail; to <mask> a flag or an ensign, as in token of surrender; to <mask> a yard or a topmast in a gale; to <mask> a tent; to <mask> the centering of an arch
hypothesis: the best context for <mask> here is To cause or produce by a stroke, or suddenly, as by a stroke; but not To lower; to let or take down; to remove.