I don't know if I am the one whom, in the past, you took note of in this regard or not. Nevertheless, that definition certainly qualifies as common usage. Most people use the word "theory" in a manner that implies lack of certitude.
My point is, even under a strictly scientific definition of "theory," which denotes great certitude, evolutionism does not qualify. Evolutionism has hijacked the word "theory" much as certain Islamic folks, not to mention innumerable kooky cults, quasi-religions, and astrologers, have hijacked theology.
Hmmm. Y'all better get together on your story. You say that "theory" is a higher standard that is not met by evolution while your buddies say that evolution is 'just a theory' indicating that 'theory' is a low standard of judgement. Which is it?