Other forms: eardrums
The eardrum is the tiny skin inside your ear that sound makes tremble. Burst an eardrum, a perforated eardrum, the eardrum vibrates.
It is about a centimetre across and moves less than the width of an atom for a quiet sound. A burst one usually heals by itself within weeks, which is why the injury is less serious than it sounds, and pressure rather than noise is the usual cause.
1nouneardrumThe tiny skin inside your ear that sound makes tremble.
“The explosion was so loud that it damaged his eardrum.”
eardrum is a body part.
Ear plus drum, a plain description of what the membrane does.
From ear + drum.
Etymology from Wiktionary, CC BY-SA