the GNU version of the Collaborative International Dictionary of English
adj. Discovered by Eustachius.
adj. Pertaining to the Eustachian tube.
The Century Dictionary and Cyclopedia
Pertaining to or named from Bartolomeo Eustachio, an Italian anatomist (died 1574).
Word Usage
"On an airplane a baby may cry for their usual reasons, but they may also experience ear pain due to their narrower eustachian tubes behind the eardrum becoming blocked."