1. in a manner showing surprise, shock, or astonishment with the mouth open
Usage: informal; often used to describe a surprised or amazed reaction
2. in a manner that is frank, candid, or unguarded in speech
Usage: informal; less common usage

Examples

• She stared openmouthedly at the magician's trick, unable to believe what she had just witnessed.
• The audience watched openmouthedly as the acrobat performed the dangerous stunt.
• He gaped openmouthedly when he heard the unexpected news.
• The children stood openmouthedly in front of the enormous dinosaur skeleton at the museum.
• She listened openmouthedly to his confession, too shocked to respond immediately.
• The crowd reacted openmouthedly to the surprise announcement.