What does 開封 mean?
開封 is a Japanese noun meaning “opening (a letter, parcel, etc.); breaking the seal” in English. It can also be translated as “unboxing (a product), unsealed mail” depending on context. It is written as 開封 in kanji, かいふう in hiragana, and kaifuu in romaji. This word is part of JLPT N1 vocabulary.
Example sentence
彼はその手紙を開封しないで送り返した。
He sent the letter back unopened.