One of the most misused terms nowadays, even by economists, is the term "hyperinflation." People have actually referred to the high inflation of the late 1970s as hyperinflation. It wasn't even close. Here's what Michael Salemi wrote in his article "Hyperinflation" in the Concise Encyclopedia of Economics:
Although the threshold is arbitrary, economists generally reserve the term "hyperinflation" to describe episodes when the monthly inflation rate is greater than 50 percent.
I had been meaning to write this post for the last few weeks and, interestingly, what reminded me was a question on Jeopardy last night in which Philip Cagan was identified as the person who defined hyperinflation the way Michael Salemi did above.