The term 'Yoga Pose with an Arched Back' can be summarized as the COBRA Pose, which is a five-letter word. The COBRA Pose is a yoga posture that involves lying on the stomach and arching the back while keeping the arms and legs straight. It is a popular pose in many yoga practices, as it helps to strengthen the spine and improve flexibility. Additionally, it can help to reduce stress and improve overall wellbeing.