I am sure we all have heard, at some point, someone saying, 'I have a theory about X. I think....'. Since I am Masters' student, I now know very well that a theory is a system of ideas that has been verified systematically (/experimentally) to be an explanation of some phenomenon, like the theory of gravitation. Therefore, the word should not be used so loosely as is done in popular culture today.
I realize that this meaning of theory, as 'an idea used to account for a situation or justify a course of action' is recognized, but especially when talking in a scientific context, it seems somewhat inappropriate to use it with that meaning - since I am using also that word for meaning something far more specific. Also, the fact that there are dozens of websites claiming this use to be somewhat incorrect, has some significance.
Moreover, Merriam-Webster notes -
However, there are two senses of theory which are sometimes troublesome. These are the senses which are defined as “a plausible or scientifically acceptable general principle or body of principles offered to explain phenomena” and “an unproven assumption; conjecture.”
So my question is, what would be a better replacement, in a situation where someone is trying to pose his/her "theory" about something? I was initially thinking using idea, but it lacks the sense that it's supposed to be an explanation. I was also thinking something like hypothesis or conjecture, but I wasn't sure.