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]

WordNet (r) 3.0 (2006):

Pepsi Cola
    n 1: Pepsi Cola is a trademarked cola [syn: Pepsi, Pepsi
         Cola]