Anatomy, Zoology .

the outer region of an organ or structure, as the outer portion of the kidney.

the cerebral cortex.

Botany .

the portion of a stem between the epidermis and the vascular tissue; bark.

any outer layer, as rind.

Mycology . the surface tissue layer of a fungus or lichen, composed of massed hyphal cells.

noun

bark , layer , peridium , rind