What Can They Mean?

One of my college Linguistics professors told us when someone is studying a different language and they come to a term the native speakers can't define it means the word represents a concept  absolutely basic to that culture. In recent years there have been several terms we used to define easily in American English that people no longer agree on. For instance there have been conflicts about what it means to be dead, how to define a human being, and the meaning of the word "marriage." Although our country has been a "melting pot" made up of immigrants from all over the world, most of us have always agreed on the definitions of those basic terms. But things don't stay the same and our world is certainly changing. In fact there have probably been more changes in the last hundred and fifty years than in the preceding thousand years. I predict that it will be quite a while before we can ever agree on those basic terms again.