Source : Webster's Revised Unabridged Dictionary (1913)

Asterion \As*te"ri*on\, n. [Gr. 'aste`rion starry.] (Anat.)
   The point on the side of the skull where the lambdoid,
   parieto-mastoid and occipito-mastoid sutures.

Source : WordNet®

asterion
     n : the craniometric point at the junction of the lamboid suture
         and the occipitomastoid suture and the parietomastoid
         suture