Well, I don’t personally define the word, but here are some actual definitions:
“Inflation is a gradual loss of purchasing power that is reflected in a broad rise in prices for goods and services over time.” (Investopedia)
“Inflation is the rate of increase in prices over a given period of time. Inflation is typically a broad measure, such as the overall increase in prices or the increase in the cost of living in a country.” (IMF)
Increasing the monetary supply can lead to inflation but it’s not the only cause and assuming it is can lead to misunderstanding the economic situation.