A fork of Rural Dictionary
"I didn't fap or have sex for two whole weeks. When I finally came, it was a knee-buckler!"
-associated with an intense sensation (usually due to sense of touch) where one experiences an extremely pleasant feeling to the point where involuntary contraction of muscles occur.
-event that make someone buckle his knees
..the way she ran her hands down my hips was an absolute knee buckler
Cathy used those great DSL'S to give me a "knee buckler" last night.