Source : Webster's Revised Unabridged Dictionary (1913)

Nicotidine \Ni*cot"i*dine\ (? or ?), n. [Nicotine + pyridine.]
   (Chem.)
   A complex, oily, nitrogenous base, isomeric with nicotine,
   and obtained by the reduction of certain derivatives of the
   pyridine group.