Is there a standard accepted definition of "soul"?

When I've talked to people about whether "the soul" exists, I've often been told that I can only use that word to refer to a non-physical thing that can exist independently of physical structures like the human brain. I find this odd because it seems to me than any sort of consciousness could be considered "soul," and the requirement that it be non-physical seems arbitrary to me. I'm especially confused because different cultures have very different ideas that are analogous to the "soul" and could be translated as such, and I don't understand why non-physicality would be a sticking point.

It seems like people are just arbitrarily defining "soul" as "whatever is most similar to the modern Christian concept," but I've been told that I'm "redefining" something mundane in a dishonest way. Am I missing something?