What does 反～ mean?
反～ is a Japanese prefix meaning “anti ~, counter ~” in English. It is written as 反～ in kanji, はん～ in hiragana, and han～ in romaji. This word is part of JLPT N2 vocabulary.
Example sentence
トムは水に飛び込んで反対側まで泳いだ。
Tom dove into the water and swam to the other side.