Younger Brother
Little Brother
noun
The kanji and the word are exactly the same. That means they share meanings as well.
おとうと
Since this word is made up of a single kanji, it should use the kun'yomi reading. When learning the kanji, you didn't learn that reading, so here's a mnemonic to help you with this word:
You look at your younger brother. He's a scheming one. He's smiling up at you. Why? Because he's lit a firecracker on your foot. It explodes, sending your toe flying. You yell "OH. Toe? TOE!" (おとうと) as you realize what's going on.
わたしの弟は、テレビを見ない。
My little brother doesn’t watch TV.
その青いかみの青年はぼくの弟です。
That young man with blue hair is my younger brother.
弟がビリヤードのボールを頭に投げつけてきたので、昨夜僕は病院に行くはめになった。
I ended up going to the hospital last night because my younger brother threw a pool ball at my head.