My definition of a theist is anybody with a god belief, which is why I include deists as a subset of theists, along with polytheists, pantheists, panentheists, and henotheists. Limiting the word theist to mean an interventionalist monotheistic deity makes the word less useful in my estimation. I need a word to describe all people that believe in gods of any kind, and theist seems to fit that bill just fine. When I want to refer to interventionalist monotheistic deities to the exclusion of all other types of deities, then I will use that phrase.
That definition can be improved by removing the word disbelieves., assuming by that that one means claims that no god or gods exist. Such people are a subset of the population of people with no god belief, and their active disbelief is not an essential aspect of atheism, and therefore need not be mentioned in the definition.
What we have been told is how you choose to use the words. Clearly, others here have different preferences.
Why do you think that others should accede to your preferences? I've already stated that my choices work for me, and have no reason to make any adjustments. I'd need to be shown why a different formulation was more illuminating to feel otherwise. I can't see a reason to define a theist in any other way than as somebody with a god belief, nor to exclude deists from that category, so I don't.
You have converted A accepts B to A is defined by B.
You seem to be defining A (theism) as not merely including those who believe in an interventionalist god, but limited to them, which allows you to exclude deists from theism. That's all well and good, but not meaningful to those that define theism as the state of holding a god belief. To those not accepting that theism is limited to interventionalist gods, which is presumably your target audience, this argument is not persuasive.
Try rewriting your argument in syllogistic form and the problem becomes more apparent. Perhaps it would look like this:
P1: Theists are exclusively people that believe in interventionalist gods.
P2: Deists don't believe in interventionalist gods.
C: Therefore deists aren't theists.
The argument is valid because its conclusion is correct if its premises are granted, but unsound if the premises are not granted.
And as you can see from this thread, many do not.
A simple and useful definition of a god (excluding pantheonic minor gods like Loki) is a conscious agent that is the source of this or any other universe. That's something that is relatively clear and easily worked with.
