breaking down, breaking open (of a door etc.); breaking through (enemy lines); driving in (of a stake, post etc.); sinking (of foundations); recess, nook, cranny; dip, slide
any device, contraption or machinery, particularly a complex, dangerous or powerful one; a piece of military equipment; a piece of heavy machinery; any object whose name or function is unknown; a thingy; a gizmo; tool (penis)