anyone can use any word. making sense has little or nothing to do with it. how can an athiest use the word "god", is like asking how can a religionist use the word "athiest". it is, in both cases, the question that is nonsense.
I use the word "god" when in conversation with a believer who appears to be in need of input from an atheist to address their spiritual issues. I also use the term to "dumb down" what I practice as a secular "Monk." (I'm just LARPING it, folks!) I'm an atheist but I am not anti-religion. As long as you keep it personal, I think religion is an excellent placeholder for inner work, spiritual learning, and Panpsychism, which I do have a degree of belief in. And Panpsychism is just Pantheism without a singular godhead. We are all part of each other's experience as conscious beings. So it is useful to use theist terms when trying to come to an understanding in conversation. I've been a very confrontational person towards believers in that past. I no longer have the desire to do that. All religion is is LARPing and fandom to a particular mythological cannon. I view it as a placeholder and something we all have to work through to arrive at a broader truth.
I'm a Christian, but I meet monthly with a group of atheists and agnostics for Bible study and related topics. God and religion is what we mostly talk about. Obviously, atheists and agnostics have a different take on the subject than religious folks. But after all, atheism and agnosticism are defined in terms of their positions toward God.
in reference to those who pretend to know more then is known and demand everyone else do so as well. who lack the humility to admit, as we all do, we are each capable of error. their existence or non-existence, and anything else about them, do not depend in any way on what we claim to know about then, nor attempt to persuade others to claim that they do. remove the fog and it becomes obvious there can be gods unlike any conceived in any known forms of belief. nothing in the unknown being unknown to prevent them from doing so. it is only our own fallible egos that along stand in the way of recognizing this. an honest mind is an open mind, and likewise the converse.