The protective outer layer of the skin. In invertebrate animals, the epidermis is made up of a single layer of cells. In vertebrates, it is made up of many layers of cells and overlies the dermis. Hair and feathers grow from the epidermis.
The outer layer of cells of the stems, roots, and leaves of plants. In most plants, the epidermis is a single layer of cells set close together to protect the plant from water loss, invasion by fungi, and physical damage. The epidermis that is exposed to air is covered with a protective substance called cuticle. See more at photosynthesis.