To Return
To Be Returned
intransitive verb, godan verb
Because the hiragana ends with an う sound, you know this word is a verb. The kanji itself means return and the verb vocab version is to return or to be returned. This is when something does this on its own. You aren't doing the returning of something in this case.
The reading is the same as the one you learned with the kanji.
母親が病気になったので、私は国に戻ることにしました。
I decided to return to my country because my mother got sick.