This is a most misunderstood term. Many economists, amateur and otherwise, believe monetary velocity itself is the prime reason for rising currency inflation. It is not. Monetary velocity is simply another indicator, not a cause. The cause of monetary inflation is two-fold. First is the printing of currency itself; then it is the circulation of the currency.
Currency is circulated based primarily on DEMAND. If there is no consumer demand for currency, it will not circulate. When it does circulate, monetary velocity becomes a factor. Thus, it is apparent that monetary velocity is yet another indicator of inflation but it is not a cause.
The cause of monetary inflation (beyond the actual Central Bank generation of the currency itself) is two-fold: Banks have to be willing to lend and consumers have to be willing to borrow. This is entirely within the larger parameters of Say's Law, which points out that demand can created by both sellers and buyers.
It should also be pointed out that this explanation is the "classical" one in the sense that it includes banks. But banks are actually artificial points of distribution within a fiat money environment. Central banks have to distribute the money they have created (either via the printing press or at the touch of an electronic button) and they choose to do so through "banks."
In truth, central banks could distribute money-from-nothing directly to consumers. It is claimed that if that happened there would be tremendous price inflation; in actuality, that would depend on how much was printed and how quickly consumers spent the "money" they received.
In truth, central bankers will NEVER distribute money directly to consumers because doing so would make clear how the modern money mechanism works; governments and their mainstream media accomplices do their very best to make sure does not happen. It would soon become apparent to people that central bankers can create as much money as they wish when they wish. It would bring up issues of what real honest money really is – gold and silver, in actuality – and why. It would make clear that central bankers have hijacked the process of money creation and ultimately expose their primary agenda of installing a one-world government, all made possible by controlling the financing spigot. The spread of such knowledge cannot and will not be willingly tolerated by the power elite.