Ladder (noun)

1. A piece of equipment consisting of two long poles with steps between them, used for climbing up or down something.
2. A structure or series of steps that allow people or things to move to a higher or lower level.
3. A series of rungs or rounds on a rope or cable on which a person can climb up or slide down.

Origin:

Old english hlæder, of germanic origin; related to dutch ladder and german leiter.

Examples:

1. He climbed the ladder to the top of the building.
2. The ladder to success.
3. The ladder of the fire truck.
4. The ladder of the swimming pool.
5. The ladder of the library shelves.