The Roman Empire faced many economic problems in its last days, including a drastic decrease in the value of Roman coins, while prices on most goods sharply increased. What is the term used to describe this problem?

Inflation

Explanation:

"A devaluation leads to a decline in the value of a currency making exports more competitive and imports more expensive. Generally, a devaluation is likely to contribute to inflationary pressures because of higher import prices and rising demand for exports."

The example is an describes Inflation.