To turn someone's statement around and use it against them.
OR
To shoot someone down while they're feeling good
Person1: YEA!!! (puts hand up for a high 5)
You: (look at person1) Ummm, no (that's a curve
OR
Person1: You look good today!
Person2: Thank you!
You: (look at them funny) No you dont...
Random Person: CURVE
by TrueUnknownartist December 20, 2009