To give off means to send out or release something, usually light, heat, smell, or a feeling. A campfire gives off warmth and light. Freshly baked cookies give off a delicious smell that fills the whole house. A radioactive substance gives off invisible energy called radiation.

The phrase works for things you can measure, like when scientists say the sun gives off enormous amounts of heat. But it also works for impressions and feelings. Someone might give off an air of confidence when they walk into a room with their head held high, or give off a friendly vibe that makes others want to talk to them. A creepy abandoned house might give off an eerie feeling that makes you want to stay away.

When you say something gives off a certain quality, you're describing what it naturally releases or projects. It's similar to emit, though give off sounds more casual and everyday.