Should theory be the appropriate term? I mean, for example, because of the quantum field theory we have been able to find the subatomic particles that it theorized and make the Standard Model. Why then is is labeled as a theory? Also wave-particle duality is widely accepted fact yet labeled as a theory. What is up with that, why call it a theory. Maybe because it promotes the fact of idealism?
"Scientific theories are testable and make falsifiable predictions. They describe the causal elements responsible for a particular natural phenomenon, and are used to explain and predict aspects of the physical universe or specific areas of inquiry[...]. Scientists use theories as a foundation to gain further scientific knowledge, as well as to accomplish goals such as inventing technology or curing disease. Scientific theories are the most reliable, rigorous, and comprehensive form of scientific knowledge. This is significantly different from the common usage of the word "theory", which implies that something is a guess "
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.