a. Nat. Hist. [ad. F. tympaniforme (Cuvier), f. TYMPANUM + -forme, -FORM.] Having the form of a drum, or (usually) of a drum-head; stretched like a drum-head: spec. applied to certain membranes in the bronchi of birds.
1854. Bushnan, in Circ. Sc. (c. 1865), I. 291/1. It is to this usually large portion of the wall of each bronchus that Cuvier gives the name, tympaniform membrane.
1893. Newton, Dict. Birds, 58. In almost all birds … the bronchi are strengthened by cartilaginous semirings; the ends of these … are closed by the inner tympaniform membrane. Ibid., 940. Syrinx trachealis.… Both inner and outer tympaniform membranes exist in the Bronchi.
1900. in B. D. Jackson, Gloss. Bot. Terms.
