Solipsism (pronounced: // (listen)) is the view that a person has no reason to believe anything exists except their own mind. It is a theory that first appeared in ancient philosophy. It mainly means to reject or doubt that other people exist. "Solus" and "ipse" are the Latin words for "alone" and "self", which is where the word "solipsism" comes from. Some kinds of solipsism say that everything outside a person's own mind (including other people) is only imaginary. Other kinds of solipsism instead say that nothing outside a person's own mind is certain.
Denial of material existence, in itself, is not solipsism. Solipsism also rejects or doubts that other people exist. As an epistemological view, it is the concept that nothing but one's own mind can be certain to exist. The existence of other minds, in this view, is considered a possibility, but not certainty. And even time does not stop just because there would be nobody to experience it (which is probably going to happen in the end of the universe when there would be simply nothing)