means The general rise in prices over time, which steadily reduces how much each unit of your money can actually buy.

from From the Latin 'inflare,' meaning 'to blow into' or 'to inflate'—'in-' (into) plus 'flare' (to blow). The image is literal: a balloon swelling with air. For centuries it meant any kind of puffing-up or swelling, including bodily and rhetorical bloat. Its specifically monetary sense—prices and money supply ballooning together—took hold in economic English in the 19th century, especially in the United States, where the idea of currency 'inflated' beyond its backing made the metaphor stick.