Dude
Guy
pronoun, の adjective
The kanji and the word are exactly the same. That means they share meanings as well.
Since this word is made up of a single kanji, it probably uses the kun'yomi reading. You did not learn this reading, so here's a mnemonic to help you to remember:
Some dude... he did it two times. Yah, two (やつ) times.
This can seem kind of derogatory, if you say it the wrong way. But as long as you're duding to your dude friends and not your no-dude boss, you should be a-okay to dude-bro it up!
宝くじが当たってから、奴は数週間最高の気分を味わったんだ。
After winning the lottery, that dude was on a high for weeks.