ladder

A frame, usually portable, of wood, metal, or rope, used for ascent and descent, consisting of two side pieces to which are fastened rungs (cross strips or rounds acting as steps).

A series of stages by which one progresses to a better position.

The hierarchy or ranking system within an organization, such as the corporate ladder.

To arrange or form into a shape of a ladder.

To ascend (a building, a wall, etc.) using a ladder.

Of a knitted garment: to develop a ladder as a result of a broken thread.

"Oh damn it, I've laddered my tights!"