どうし 同士 Common word JLPT N1 LinksSentence search for 同士Sentence search for どうしSentence search for どしKanji details for 同 and 士Edit in JMdict Noun, Noun, used as a suffix1. fellow; mutual; companion; comradeOther forms同士 【どし】Notesどし: Out-dated or obsolete kana usage. Discussions Log in to talk about this word.