同 is one of the most commonly used Japanese kanji, and it also has a lot of special readings in addition to the standard onyomi and kunyomi readings.
ONYOMI 音読み
おな.じ ona.ji
KUNYOMI 訓読み
ドウ dou
Examples
英語はドイツ語と同語族である。The English language is cognate to the German language.同世代の人は、仕事とか、買い物で留守ばかりです。My contemporaries are, working, shopping, out and about, all the time.