The ethmoidal labyrinth is a part of the nasal cavity located between the eyes. It is made up of a series of small air-filled spaces called ethmoid air cells, which are lined with a mucous membrane that helps to warm and moisten the air we breathe. synonyms for ethmoidal labyrinth include the ethmoid complex, ethmoid sinus, or simply the ethmoid bone. These synonyms are often used interchangeably in medical literature and discussions, and all refer to the same general area of the human anatomy. While the ethmoidal labyrinth may seem like a small and unimportant part of the body, it plays a crucial role in our respiratory health.