The Collaborative International Dictionary of English v.0.48:

Pepsi Cola \Pepsi Cola\, Pepsi-Cola \Pepsi-Cola\prop. n. [A
   trademark of the Pepsi-Cola Corporation.]
   A carbonated soft drink flavored by extract from the cola nut
   (kola nut). The nut is found on trees of the species Cola
   acuminata and Cola nitida. [Trademark]

   Syn: Pepsi
        [WordNet 1.5 + PJC]

The Collaborative International Dictionary of English v.0.48:

Cola nut \Cola nut\, Cola seed \Cola seed\ . (Bot.)
   The bitter fruit of Cola acuminata, which is nearly as
   large as a chestnut, and furnishes a stimulant, which is used
   in medicine.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

Cola acuminata
    n 1: tree bearing large brown nuts containing e.g. caffeine;
         source of cola extract [syn: kola, kola nut, kola nut
         tree, goora nut, Cola acuminata]