The outermost single layer of cells that overlap one another like shingles in hair is called the stratum corneum.

This layer is the outermost layer of the epidermis, the skin's outermost layer.

Here are some key characteristics of the stratum corneum:

* Made of dead cells: These cells are filled with a tough protein called keratin.

* Highly compacted: The cells are tightly packed together, forming a barrier that protects the body from the environment.

* Continuously shed: As new cells are produced in the deeper layers of the epidermis, older cells in the stratum corneum are shed. This process helps to maintain the integrity of the skin barrier.

The shingle-like overlapping arrangement of the stratum corneum cells is called imbrication. This arrangement provides additional strength and flexibility to the skin.