What does 天然 mean?
天然 is a Japanese noun meaning “nature, spontaneity” in English. It can also be translated as “natural airhead” depending on context. It is written as 天然 in kanji, てんねん in hiragana, and tennen in romaji. This word is part of JLPT N3 vocabulary.
Example sentence
この車は天然ガスで動く。
This car runs on natural gas.