It's the same thing though. We just speak different versions.
It's like splitting up a nation. People in the north might use a word a different way that people in the south but it's the same word. Language develops based on individual need.
So when we say 'trip' and say it means hallucinations it's more specifically "the sensation of experiencing hallucinations that take you on a mental journey." We chose this word to represent this because of the journey part.