Source : Webster's Revised Unabridged Dictionary (1913)

Nasion \Na*si*on\, n. [Nl., fr. L. nasus nose.] (Anat.)
   The middle point of the nasofrontal suture.

Source : WordNet®

nasion
     n : the craniometric point at the bridge of the nose where the
         frontal and nasal bones of the skull meet