SAG'ITTAL, adjective [Latin sagittalis, from sagitta, an arrow; that which is thrown or driven, probably from the root of say and sing.] Pertaining to an arrow; resembling an arrow; as sagittal bars of yellow. In anatomy, the sagittal suture is the suture which unites the parietal bones of the skull.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI