The rubber lip or strip commonly found on the edges of kitchen cabinet doors is called a "cabinet door bumper" or "cabinet door stop." It serves as a cushion or buffer when the cabinet door is closed, preventing it from slamming shut and reducing noise and impact. Cabinet door bumpers are typically made of rubber or soft materials and come in various shapes and sizes. They are adhesive-backed for easy installation and are a simple and cost-effective way to protect your cabinets and dampen the sound when closing the doors.