Fungible

If I were a word, I don’t wanna have a synonym,
Substitutable by any words that seem to look the same,
Delenda, growlery, haecceity, surely are irreplaceable,
I want to be just like them, words rarely fungible.
Love tricks us to believe it’s sticky, constant and for long,
But like friendships, they either go on or say ‘so long’,
Expiry isn’t solely for medicines, but romance,
Even stunning stars fall into inevitable demise.