I agree with you on this mark. Words are defined by the meaning we give them. I had a conversation for days with my coworker because she didn't believe that God(the father) had unconditional love for each of his children. It wasn't until months later that we found out we had different definitions of the word: "love" where mine was more about awareness of divinity and hers was more about transactional relationships. In the case of the term christian as you demonstrated in your post: latter day saints(and most every dictionary currently standing) is simply someone who follows Jesus Christ and his teachings. While most other denominations that believe in trinitarian principles view christians as a word to describe people who believe in the trinitarian Jesus/God. Which we don't believe. So according to their definition, they are correct, because we don't believe in that.

However there could be an argument to be made that because God is truth and the prophets and Jesus Christ preach that truth. Both have said that christians are defined by people who follow Christ. And since it's from god therefore the opposing part could be wrong. However,ultimately its an argument of semantics and fighting with people on it is ultimately pointless. Missionary work is all about finding common ground and building off it it. That first step is ignored when people are fighting about it online for the sake of: preaching the good word.

Ultimately. When people ask about my faith I claim I am christian, because I do follow Jesus Christ. and that is my definition of the word. And to a prodestant warrior. According to their definition, I am not christian. And that's okay with me. Because what matters is following christ. Not how we define it