Definition of eustachian tubes:
(n) :
(anatomy) In humans and other land vertebrates, a tube that links the nasopharynx to the cavity of the middle ear to allow the equalization of the pressure on both sides of the eardrum.
(n) :
Alternative letter-case form of Eustachian tube. [(anatomy) In humans and other land vertebrates, a tube that links the nasopharynx to the cavity of the middle ear to allow the equalization of the pressure on both sides of the eardrum.]