noun (n)

• the layer of unmyelinated neurons (the grey matter) forming the cortex of the cerebrum(noun.body)

  Synonym:
  cerebral cortex, cerebral mantle, pallium
  

  source: wordnet30
• the tissue forming the outer layer of an organ or structure in plant or animal(noun.body)

  Antonym:
  medulla
  

  source: wordnet30
• the tissue that surrounds the lens nucleus(noun.body)

  Synonym:
  lens cortex
  

  source: wordnet30
• Bark, as of a tree; hence, an outer covering.(noun)

  source: webster1913