Determine the Meaning of 'Fluttered'

On a bright morning, Sam decided to go to the park. He brought his favorite toy, a colorful kite. As he ran through the grass, the kite soared into the sky, dancing with the wind. Sam giggled with delight as the kite fluttered above him.

Soon, some of his friends came to join him. They took turns flying the kite and laughed when it twisted and turned in the air. Together they created a fun game, trying to see who could keep the kite flying the longest.