Tympanums

1 definition found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Tympanum \Tym"pa*num\, n.; pl. E. {Tympanums}, L. {Tympana}.
     [L., a kettledrum, a drum or wheel in machines, the
     triangular area in a pediment, the panel of a door, Gr.
     ty`mpanon, ty`panon, fr. ? to strike, beat. See {Type}, and
     cf. {Timbrel}.]
     1. (Anat.)


        (a) The ear drum, or middle ear. Sometimes applied
            incorrectly to the tympanic membrane. See {Ear}.
        (b) A chamber in the anterior part of the syrinx of birds.
            [1913 Webster]
  
     2. (Zool.) One of the naked, inflatable air sacs on the neck
        of the prairie chicken and other species of grouse.
        [1913 Webster]
  
     3. (Arch.)
        (a) The recessed face of a pediment within the frame made
            by the upper and lower cornices, being usually a
            triangular space or table.
        (b) The space within an arch, and above a lintel or a
            subordinate arch, spanning the opening below the arch.
            [1913 Webster]
  
     4. (Mech.) A drum-shaped wheel with spirally curved
        partitions by which water is raised to the axis when the
        wheel revolves with the lower part of the circumference
        submerged, -- used for raising water, as for irrigation.
        [1913 Webster]