/ˈd(y)o͝orə/
Noun
1. (Anatomy)
The dura mater, the outer covering of the brain and spinal cord. (wiktionary.org)
2. Dura mater. The outermost (and toughest) of the 3 meninges. (wordnetweb.princeton.edu)
3. A thin membrane that is the outermost of the three layers of the meninges that surround the brain and spinal cord. It is derived from mesoderm. (wikipedia.org)
Word Origin: Latin Fem. Of durus, hard