The Collaborative International Dictionary of English v.0.48:

Timpano \Tim"pa*no\, n.; pl. Timpani. [It.] (Mus.)
   See Tympano.
   [1913 Webster] Timur

The Collaborative International Dictionary of English v.0.48:

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.]
   [1913 Webster]