Source : Webster's Revised Unabridged Dictionary (1913)

Credo \Cre"do\ (kr?"d?), n. [L. See {Creed}.]
   The creed, as sung or read in the Roman Catholic church.

         He repeated Aves and Credos.             --Macaulay.

Source : WordNet®

credo
     n : any system of principles or beliefs [syn: {creed}]