cortex

Concise Oxford English Dictionary © 2008 Oxford University Press:
cortex /ˈkɔːtɛks/

▶noun (pl. cortices /-tɪˌsiːz/)

• 1 Anatomy the outer layer of an organ or structure, such as a kidney or adrenal gland.

  ■ (also cerebral cortex) the outer, folded layer of the cerebrum, which plays an important role in consciousness.

• 2 Botany an outer layer of tissue immediately below the epidermis of a stem or root.

– derivatives
cortical adjective.

– origin ME: from L., lit. ‘bark’.