Definition of "nonfungible"

Horses, slaves, and so forth, are non-fungible things, because they differ individually in value and cannot be exchanged indifferently one for another.

1880, Thomas Erskine Holland, The Elements of Jurisprudence, 12th edition, Oxford: Clarendon Press, published 1916, page 107

But the claim that love of certain sorts—romantic, maternal, filial—is nonfungible means that this emotion is directed only to the particular individuals who manifest those properties.

2019, Carolyn Korsmeyer, Things: In Touch with the Past, Oxford University Press, page 100