A decrease in the rate of inflation for an economy over time. Disinflation occurs when the increase in the main price index of a country (e.g. UK CPI) slows down from the previous period is measured over.
This should not be confused with the term deflation. Because even if the inflation rate has slowed down from 2.2% to 1.5%, the general prices of everyday goods will still be increasing by 1.5% despite the lower figure.