cortex vs rind

cortex

noun
  • The outer surface of a piece of flint. 

  • The tissue of a stem or root that lies inward from the epidermis, but exterior to the vascular tissue. 

  • The outer layer of an internal organ or body structure, such as the kidney or the brain. 

rind

noun
  • The gall, the crust, the insolence; often as "the immortal rind" 

  • tree bark 

  • A hard, tough outer layer, particularly on food such as fruit, cheese, etc 

  • An iron support fitting used on the upper millstone of a grist mill. 

verb
  • To remove the rind from. 

How often have the words cortex and rind occurred in a corpus of books? (source: Google Ngram Viewer )