It sounds like a fun word, but what does it mean? If I had to guess, I’d say…
adj. Likely to become covered with mold or fungus. As in, “Don’t bother saving the leftover beets. They’re fungible.”
But alas, it is not about fun or fungus.
“Fungible” can be an adjective or a noun. As an adjective, its most basic meaning is “interchangeable.” As a noun, it describes an item that is interchangeable with another item of the same kind.
I had a hard time grasping the concept of fungibility. Many of the definitions I found used grain as an example, saying that a particular amount of grain had the same value as another like amount of the same grain. And I said, “Why would anyone want to trade like amounts of the same grain? What would be the point?” So I had to think about it for a while. It helped to realize that the word is most often used by investors and lawyers.
I think what it means is that if I owed you a dollar, you wouldn’t care which dollar bill I gave you. Any American dollar bill would do, though you might be offended if I gave you one covered with goo. Dollar bills are fungible. Similarly, if I had corn from Nebraska and you had the same kind of corn from Kansas, our corn would be fungible on the market. That is, it would be traded at exactly the same value because, for most intents and purposes, 100 pounds of corn is 100 pounds of corn.
So I guess the only way that fungibility relates to fungus is when 100 pounds of shiitake is 100 pounds of shiitake.