Definition of sphenoid in English:


(also sphenoid bone)

Pronunciation /ˈsfēnoid/ /ˈsfinɔɪd/


  • A compound bone that forms the base of the cranium, behind the eye and below the front part of the brain. It has two pairs of broad lateral “wings” and a number of other projections, and contains two air-filled sinuses.

    • ‘A large groove (sinus of Breschet) may occur on the intracranial face, parallel to the coronal suture and extending from the bregma to the lesser wing of the sphenoid.’
    • ‘Another such feature are the deep internasal cavities on either side of the sphenoid.’
    • ‘Metastasis to the brain can occur by way of Batson's plexus or by direct extension from adjacent structures such as the sphenoid bone or sinuses.’
    • ‘It is attached superiorly to the spine of the sphenoid and the region of the petrotympanic fissure.’
    • ‘Somewhat further back, the dura has been separated from the body of the sphenoid bone.’


  • Relating to the sphenoid bone.

    • ‘The maxillary sinus is most commonly involved; however, most patients with radiologic maxillary sinusitis have abnormalities of the ethmoid and sphenoid sinuses.’
    • ‘Magnetic resonance imaging showed a mass bilaterally in the nasopharynx and the sphenoid sinuses.’
    • ‘Its accuracy, however, is questionable in suspected ethmoid, frontal, or sphenoid involvement.’
    • ‘Further CT scans have not demonstrated any additional sphenoid sinus or skull base erosion nor recurrent tumour five years after surgery.’
    • ‘In 1998, the tumor recurred with involvement of the nasal cavity and sphenoid and ethmoid sinuses.’


Mid 18th century from modern Latin sphenoides, from Greek sphēnoeidēs, from sphēn ‘wedge’.



/ˈsfēnoid/ /ˈsfinɔɪd/