What does 単なる mean?
単なる is a Japanese adjective meaning “mere, simple, sheer” in English. It is written as 単なる in kanji, たんなる in hiragana, and tannaru in romaji. This word is part of JLPT N3 vocabulary.
Example sentence
それは単なる偶然だと思う。
I think it is a mere coincidence.