Answer:
The answer to the question: What does it mean to say that the coinage had become debased, would be: that literally, the value of the coins was nil as the amount of gold, or silver, present in them, was almost nonexistent, being replaced by worthless metals. It means that if anyone was paid using these coins, they would not get the real worth of what they were being paid for, as the coin used had no value.
Step-by-step explanation:
When talking about money, and especially in ancient times when things were paid with actual coins made out of precious metals like gold, or silver, we are talking about the fact that these coins were worth something because of the metals used to produce them. During Diocletian´s time, because of the little availability of these precious metals, the worth of the coins used to pay for services and for goods, was nule. When money, or currency, has that problem, there is nothing to back it up, and justify its worth, then it is called a debasement of coinage.