Grey Matter Meaning

(neuroanatomy) A collection of cell bodies and (usually) dendritic connections, in contrast to white matter.

Example: 1904, Lucy Maud Montgomery, "Penelope's Party Waist" in Short Stories: 1904:
  "I'd better be putting my grey matter into that algebra instead of wasting it plotting for a party dress that I certainly can't get."
1914,Sax Rohmer, The Sins of Severac Bablon, ch. 10:
  "Inspector Pepys!" gasped Bernard Megger, swallowing between the words, "I shall remember you!"
  "You will be wasting grey matter!" replied the man.
2001 Sep. 28, Thomas K. Grose, "Connect the Dots," Time:
  How many phone numbers are stored in your grey matter?