ethmoid sinus

Definition of ethmoid sinus

ethmoid sinus

(ETH-moyd SY-nus)
A type of paranasal sinus (a hollow space in the bones around the nose). Ethmoid sinuses are found in the spongy ethmoid bone in the upper part of the nose between the eyes. They are lined with cells that make mucus to keep the nose from drying out.

Source: NCI Dictionary of Cancer Terms