The word suit has several meanings:

1. A matching set of clothes, usually a jacket and pants or skirt made from the same fabric. Business people often wear suits to work. A well-fitted suit can make someone look professional and put-together. When someone says they're wearing their “Sunday best,” they might mean a suit they save for special occasions.
2. One of the four categories in a deck of playing cards: hearts, diamonds, clubs, or spades. Each suit has thirteen cards. In many card games, you need to play a card that matches the suit that was led, which means if someone plays a heart, you need to play a heart too if you have one.
3. To fit or be right for someone or something. You might say that a bright yellow backpack suits your personality, or that rainy weather suits your mood when you want to stay inside and read. When something suits you, it matches or fits well with who you are or what you need. If you describe someone as suited for a job, you mean they have the right skills and personality for it.
4. A lawsuit or legal case. When someone files a suit against another person, they're taking them to court. You might read about a company facing a suit over a defective product.