Source : Webster's Revised Unabridged Dictionary (1913)

Tombac \Tom"bac\, n. [Pg. tambaca,tambaque, fr. Malay tamb[=a]ga
   copper; cf. Skr. t[=a]mraka; cf. F. tombac.] (Metal.)
   An alloy of copper and zinc, resembling brass, and containing
   about 84 per cent of copper; -- called also {German, or
   Dutch, brass}. It is very malleable and ductile, and when
   beaten into thin leaves is sometimes called {Dutch metal}.
   The addition of arsenic makes {white tombac}. [Written also
   {tombak}, and {tambac}.]