Secretly means doing something in a way that others don't know about, keeping it hidden on purpose. When you work secretly on a surprise birthday gift for your mom, you make sure she doesn't see what you're doing. When spies operate secretly, they gather information without being detected.

The word suggests actively hiding something from others who might want to know about it. You might study secretly for a spelling bee to surprise your classmates with how well you do, or whisper secretly to share important news with just one friend.

Sometimes people do things secretly for good reasons, like planning surprises or protecting sensitive information. Other times, acting secretly can mean hiding something wrong, like when someone breaks a rule and hopes no one finds out. The word itself is neutral: whether keeping a secret is right or wrong depends on what you're hiding and why.

A secret is the thing being hidden, while secretly describes the manner of hiding it. If you secretly save money for months, the amount you've saved remains your secret until you reveal it.