The phrase is often used when describing a romantic encounter or experience. After their moonlit walk on the beach, she was completely swept off her feet.
Pro Tip 2/3
Figurative Use
The phrase doesn't mean literally lifting someone; it's about emotional impact. The crowd was swept off their feet by the stirring speech.
Pro Tip 3/3
Strong Impact
Use this phrase to express a very strong and usually positive impression. Her kindness and wit swept me off my feet.