cortex

noun pl. cortices

1. 1. the outer part or external layers of an internal organ, as of the kidney or the adrenal glands
   2. the outer layer of gray matter over most of the brain
2. Bot.
   1. a layer of tissue in the roots and stems of dicotyledonous plants, located between the stele and epidermis
   2. loosely any layer of stem tissue external to the xylem
   3. an outer layer of tissue in certain algae, lichens, and fungi
3. Pharmacy the bark or rind of a plant