Source : Webster's Revised Unabridged Dictionary (1913)

Tympano \Tym"pa*no\, n.; pl. {Tympani}. [It. timpano. See
   {Tympanum}.] (Mus.)
   A kettledrum; -- chiefly used in the plural to denote the
   kettledrums of an orchestra. See {Kettledrum}. [Written also
   {timpano}.]

Source : WordNet®

tympani
     n : a large hemispherical brass or copper percussion instrument
         with a drumhead that can be tuned by adjusting the
         tension on it [syn: {kettle}, {kettledrum}, {tympanum}, {timpani}]