Sphenoids

Part of speech: noun

Definitions

1. A pair of irregular bones located at the base of the skull, contributing to the structure of the cranial cavity and the eye sockets
2. The bones that help form the floor of the cranium and house important vascular and nervous pathways
3. A complex bone contributing to the formation of the facial skeleton, supporting various structures of the head and jaw

Etymology: The sphenoid is named for its shape: Greek "sphēn" meant "wedge," and "-eidēs" meant "-like," so "sphēnoeidēs" described something wedge-shaped. Greek anatomists used the term, and it passed into New Latin as "sphenoides," which is where English got it. Sphenoids is simply the plural of sphenoid. The bone, which sits at the base of the skull behind the eyes, is shaped somewhat like a bat or a butterfly with its wings spread, and it is wedge-like in the way it fits between neighbouring bones, which is why the name stuck.