What does 膨張 mean?
膨張 is a Japanese noun meaning “expansion, swelling, increase” in English. It is written as 膨張 in kanji, ぼうちょう in hiragana, and bouchou in romaji. This word is part of JLPT N1 vocabulary.
Example sentence
多くの天文学者は、宇宙は永遠に膨張してゆくものだと考えている。
Many astronomers assume that the universe expands infinitely.