What does 理由 mean?
理由 is a Japanese noun meaning “reason” in English. It is written as 理由 in kanji, りゆう in hiragana, and riyuu in romaji. This word is part of JLPT N4 vocabulary.
Example sentence
どうしてあなたにお詫びする理由があるのですか。
Why should I apologize to you?