Functional means working properly and doing what it's supposed to do. A functional bicycle has working brakes, inflated tires, and pedals that turn the chain. It might not be fancy or beautiful, but it gets you where you need to go. When something is functional, it serves its purpose effectively.

The word often contrasts with things that look good but don't work well. A backpack might be stylish but not very functional if its zippers break or it can't hold your books. Good design is both attractive and functional: a desk lamp that looks cool but provides plenty of light for reading or homework.

In everyday conversation, people use functional to describe systems or objects that work adequately even if they're not perfect. Your family's old computer might be slow and outdated, but if it's still functional, it can handle basic tasks like writing reports or checking email.

Sometimes functional implies something is plain or purely practical. A functional bedroom has a bed, a dresser, and a desk, but it might lack decorations or personality. When architects or designers talk about functional spaces, they mean areas organized to work efficiently for the people using them, even if that means sacrificing some beauty for usefulness.