a thick plank, used for several mechanical purposes; especially:
a plank to receive the mouth of a petard, with which it is applied to anything intended to be broken down.
a plank or beam used for supporting the earth in mines or fortifications.
Origin: f, from sp. Madero, or pg. Madeiro, fr. Sp. Madera wood for building, timber, pg. Madeira, L. Materia stuff, materials, lumber. See matter.