Wikipedia will tell you that it is pain and unpleasantness. But that is too shallow. That isn't true suffering. To me, suffering is when thoughts start causing physical pain. When the prospect of death seems like the only escape. But sometimes not even death can stop suffering.
I've been thinking about this a lot. What is the nature, the purpose of suffering. And then, it hit me. Maybe the lack of a purpose is the problem? It is easier to take pain when we know when it will end, or when we know that it is a pain of healing. But when it is a destructive pain, or suffering without a purpose, then it is true suffering. Pain for the sake of pain, where nothing is gained and everything is lost. Is that the nature of suffering? I don't know. I can't say that I experienced true suffering on that level. I don't think anyone has. Or at least they haven't lived long enough to tell the tale.
Is being stuck upside down in a cave until you slowly die, knowing nobody will come to rescue you true suffering? Is being a victim of a terrible crime and not being able to ever get justice for it true suffering? Or is it something simpler?
I was never good with words. So please don't blame me if I can't fully define it. That is exactly why I ask this question. I invite you all to discuss the essence and the nature of suffering with me. I wish to understand.
DISCLAIMER: This is a philosophical question. Nothing more, nothing less.
I think your line of reasoning falls somewhere between the "No True Scotsman" and "Persuasive Definition" logical fallacies.
While one can be aware of their own threshold for what they consider "suffering", one cannot set that threshold for anyone else. To some, a papercut may be suffering, while others may enjoy physical pain and suffer when their dog dies.
The point I'm trying to make is there is no true suffering. Suffering is whatever the sufferer says it is and it's a subjective experience, so that would apply only to them. We can, of course, generalize the idea of suffering, as Wikipedia has done in the definition you provided but again, this can really only explain the fact that suffering exists or maybe even the fact that many people consider many of the same things to be forms of suffering.
You may enjoy the teachings of Buddha, as his beginning premise is basically "all life is suffering" and his teachings largely revolve around the nature of suffering and how to accept it / overcome it.
I did not mean to look for scenarios of true suffering. That is pointless. I'm more interested in the concept itself. It's not just pain and futility. Suffering is something else, something distinct. I'm not trying to find the "true definition". I just want to know different perspectives to understand the concept better.
I do agree that the concept is subjective to a large degree, and what I am looking for are the parts that are not subjective, the "core" of the concept. Thank you for providing your perspective.