A drop knee (sometimes "Egyptian") is a body-position move where the climber turns one foot inward — usually planted on a hold to the side — and lets the knee drop down and across the body, twisting the hip flush against the wall. The position uses the leg as a brace: the body rotates around the hip and the climber gains reach without fighting against gravity with the arms.
Drop knees are essential on overhanging walls where keeping the hips into the wall is the key to conserving energy. They turn what would be a hard pulling-and-reaching move into a balance move — once the hip is in, the body weight transfers onto the lower body and the upper body can move easily.
The technique pairs naturally with heel hooks, toe hooks, and any move where the climber needs to rotate sideways to reach. Beginners often skip drop knees, finding them awkward — but learning the move pays massive dividends as soon as overhangs start. Practice on moderate overhanging routes by deliberately twisting one hip in on every move.