This is the 1216th most frequent Japanese word.
あるいは
"Or" or "possibly."
Here, 'あるいは' is used as a conjunction meaning 'or', presenting alternative possibilities.
明日は晴れるか、あるいは雨が降るかもしれません。
Tomorrow might be sunny or it might rain.
In this sentence, 'あるいは' means 'perhaps', indicating a possibility.
あるいは、あなたが正しいのかもしれません。
Perhaps you are correct.
Here, 'あるいは' is used to list options, functioning as 'or'.