Terminology doesn't matter much as long as people understand the ideas involved. You should call and idea whatever you want to call it as long as you are clear about the substance of your ideas.
Some commentators have stated that the Standard Model or other scientific results are well-grounded. So far, these ideas have not been refuted. If somebody invented a competing theory, then that theory would have to solve the same problems the current theory solves. Since the current theory solves a lot of problems that is difficult. However, any given theory is either right or wrong and no number of experimental results that agree with a theory prove it is true or that it is probably true or anything like that.
See "Realism and the Aim of Science" by Karl Popper, especially the first chapter, and on the definition issue see "Conjectures and Refutations" by Popper Chapter 3, Section 3.