Sphenoid bone Meaning, Definition & Usage

  1. noun butterfly-shaped bone at the base of the skull
    sphenoid; os sphenoidale.

WordNet

Definitions
  1. (Anat.), an irregularly shaped bone in front of the occipital in the base of the skull of the higher vertebrates. It is composed of several fetal bones which become united the adult. See Alisphenoid, Basisphenoid, Orbitosphenoid, Presphenoid.

Webster 1913