Source : Webster's Revised Unabridged Dictionary (1913)

Cinchonidine \Cin*chon"i*dine\, n. [From {Cinchona}.] (Chem.)
   One of the quinine group of alkaloids, found especially in
   red cinchona bark. It is a white crystalline substance,
   {C19H22N2O}, with a bitter taste and qualities similar to,
   but weaker than, quinine; -- sometimes called also
   {cinchonidia}.