No, not a change in prices. A change (decrease) in the purchasing power of the monetary unit (dollar). You know, the one that I have today that is worth $0.10 compared to the one my grandpa had.
Any change in one is a change in the other. If there's no change in prices then there's no change in purchasing power and we got zero inflation.
Price
Purchasing PowerAn amount of money exchanged for something of value.The Complete Real Estate Encyclopedia by Denise L. Evans, JD & O. William Evans, JD. Copyright © 2007 by The McGraw-Hill Companies, Inc.
1. The value of a currency expressed as the amount of goods or services one unit of the currency can buy. Purchasing power is important to inflation, as the higher an inflation rate is, the fewer goods and services one unit of a currency can buy. To measure purchasing power, one must compare it with an objective standard; that is, one might compare how much one dollar can buy now versus how much it could buy 10 year ago. See also: CPI, Purchasing power parity.Farlex Financial Dictionary. © 2012 Farlex, Inc. All Rights Reserved