Meaning

noun the main cavity of the ear; between the eardrum and the inner ear

noun the membrane in the ear that vibrates to sound

noun a large hemispherical brass or copper percussion instrument with a drumhead that can be tuned by adjusting the tension on it

originBorrowed from Latin tympanum (“a drum, timbrel, tambourine; the eardrum”). Doublet of timbre, timpani, timbal, and tymbal.

Etymology from Wiktionary, CC BY-SA 3.0