An object or sound is resonant when it vibrates and produces a strong, clear sound. A bell is an example of something that's often described as resonant.
When we say a place has a resonant atmosphere, we mean it feels alive with energy. For instance, if you're in a crowded cafe on a Saturday afternoon, the chatter of people can create a resonant atmosphere - everyone's talking and laughing at the same time, making the space feel energetic. If you walk into an empty concert hall where music was just performed, the acoustics can be so good that they enhance any sound, creating a resonant feeling even when it's quiet.
Resounding, echoing.
Example: From across the valley came the resonant sound of a distant church bell.
