What is "knee-on-stomach"

Knee-on-stomach, or knee-on-belly, knee-on-chest, knee-ride, knee mount (uki-gatame, 浮固, "floating hold" in budō), is a dominant ground grappling position where the top combatant places a knee on the bottom combatant's torso, and usually extends the other leg to the side for balance. This position is typically obtained from side control, simply by rising up slightly and putting a knee on the opponent's stomach or chest.