sphenoid
Concise Oxford English Dictionary © 2008 Oxford University Press:
sphenoid /ˈsfiːnɔɪd/
▶noun Anatomy a large compound bone which forms the base of the cranium.
– derivatives
sphenoidal adjective.
sphenoidal adjective.
– origin C18: from mod. L. sphenoides, from Gk sphēnoeidēs, from sphēn ‘wedge’.
'sphenoid' also found in these Oxford entries:

