The Collaborative International Dictionary of English v.0.48:

consumer price index \consumer price index\ n.
   An index of the cost of all goods and services to a typical
   consumer, calculated and published by the United States
   Bureau of Labor Statistics; abbreviated CPI, and usually
   referred to by that acronym. The Bureau maintains several
   indices for different groups of consumers, but the most
   commonly referred to is the index for "All urban consumers",
   called the CPI-U. The increase of this value each year is
   one measure of monetary inflation.

   Syn: CPI, cost-of-living index.
        [WordNet 1.5]

   Note: For a table of values from the Bureau of Labor
         Statistics of the CPI over time, see CPI-U from 1913 to
         1998.
         [PJC]

WordNet (r) 3.0 (2006):

consumer price index
    n 1: an index of the cost of all goods and services to a typical
         consumer [syn: consumer price index, CPI, cost-of-
         living index]