When someone is guarded, they're being careful about what they reveal, holding back their true thoughts or feelings. A guarded person might answer questions with short, vague responses instead of opening up, like a student who's been teased before and now stays quiet in class to avoid giving bullies more to use against them.

You can also be guarded about specific topics. Someone might be guarded about their weekend plans, not wanting to share details. A witness might give guarded answers to a lawyer's questions, choosing words carefully to avoid saying too much.

The word suggests protective caution, like keeping your cards close to your chest in a poker game. People often become guarded after being hurt or disappointed: a dog that was mistreated might act guarded around strangers, and a kid who shared a secret that got spread around school might be guarded about confiding in classmates again.

There's also a physical meaning: a guarded building has security watching it, and a guarded border has soldiers or officers protecting it. But most often, guarded describes an emotional state, that careful, protective stance people take when they're not sure it's safe to be fully honest or vulnerable.