She wore a white dress, her long hair fluttering in the wind.
Tips
usage
Reduplicating 飘 ('to float/flutter') intensifies the image - something is continuously drifting, swaying, or fluttering. Often paired with 然 as 飘飘然 to describe a person who is 'floating on cloud nine' from compliments or success.
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飘飘然 has a faintly negative tinge - suggests the person is getting carried away or full of themselves. Use carefully when describing someone's mood.