A hairdo is a particular way someone's hair is styled or arranged. When you get your hair cut, combed, braided, or shaped in a specific way, that's your hairdo. Some hairdos are simple, like a ponytail or letting your hair hang straight. Others are elaborate, like the towering wigs people wore in the 1700s or the intricate braids and twists people create today.

The word has a slightly old-fashioned, informal feel to it. You might hear your grandmother talk about getting her hairdo done at the salon, or read about fancy hairdos in older books. Today, people more often say hairstyle, though hairdo still pops up, especially when someone's hair looks particularly styled or dramatic. “Check out that hairdo!” usually means someone's hair looks noticeably different or interesting.

Getting a new hairdo can change how you feel about yourself. Some people stick with the same hairdo for years, while others experiment constantly, trying different looks as they grow and change.