[1] : The Collaborative International Dictionary of English v.0.48

dura mater \du"ra ma"ter\ l., lit., hard mother. the membrane
   was called mater, or mother, because it was formerly thought
   to give rise to every membrane of the body. anat.
   the tough, fibrous membrane, which lines the cavity of the
   skull and spinal column, and surrounds the brain and spinal
   cord; -- frequently abbreviated to dura.
   1913 webster

[2] : WordNet (r) 2.0

dura mater
     n : the outermost and toughest of the 3 meninges syn: dura
see also:
dura 

Dura Mater >> D Words
Dura Mater, definition of term: Dura Mater
dura+mater_pag1.html

Mater >> M Words
Mater, definition of term: Mater
mater_pag1.html

Dura >> D Words
Dura, definition of term: Dura
dura_pag1.html

Alma Mater >> A Words
Alma Mater, definition of term: Alma Mater
alma+mater_pag1.html