Bret Weinstein argues that the term ’theory’ should be reserved for only the hypothesis that remains when all competing hypotheses are debunked. Darwin’s Theory of Evolution is a theory since all competing explanations for the relationships between species across time (like creationism, Lamarckism, etc.) have effectively been discarded. Thus, there exists a strict criterion for some proposition to be regarded as theory.
This is fairly obvious to those with a mathematics background. In mathematics, a theorem is a statement that must be accompanied by a proof, and a theory is a collection of theorems resulting from a set of axioms. The standard for something to be considered a theory is extremely high.
Unfortunately, the word ’theory’ is tossed around carelessly in common speech as well as in academics. Divine Command Theory is at best a hypothesis, an unfalsifiable one at that. String Theory is another so-called theory. And then there are all the conspiracy theories (and the corresponding complacency theories) we might entangle ourselves in.