What does 正当 mean?
正当 is a Japanese noun meaning “just, due, proper” in English. It is written as 正当 in kanji, せいとう in hiragana, and seitou in romaji. This word is part of JLPT N1 vocabulary.
Example sentence
先生は彼女に正当な取り扱いをしなかった。
The teacher didn't do her justice.