The Collaborative International Dictionary of English v.0.48:

Sagittal \Sag"it*tal\, a. [L. sagitta an arrow: cf. F.
   sagittal.]
   1. Of or pertaining to an arrow; resembling an arrow;
      furnished with an arrowlike appendage.
      [1913 Webster]

   2. (Anat.)
      (a) Of or pertaining to the sagittal suture; in the region
          of the sagittal suture; rabdoidal; as, the sagittal
          furrow, or groove, on the inner surface of the roof of
          the skull.
      (b) In the mesial plane; mesial; as, a sagittal section of
          an animal.
          [1913 Webster]

   Sagittal suture (Anat.), the suture between the two
      parietal bones in the top of the skull; -- called also
      rabdoidal suture, and interparietal suture.
      [1913 Webster]

WordNet (r) 3.0 (2006):

interparietal suture
    n 1: the suture uniting the two parietal bones [syn: sagittal
         suture, interparietal suture, sutura sagittalis]