What does 紫外線 mean?
紫外線 is a Japanese noun meaning “ultraviolet rays” in English. It is written as 紫外線 in kanji, しがいせん in hiragana, and shigaisen in romaji. This word is part of JLPT N1 vocabulary.
Example sentence
紫外線の急激な上昇は研究者たちにオゾンホールの存在を信じさせた。
The sudden increase of ultraviolet rays made the researchers believe in the existence of ozone holes.