The term 'Sort with a Stiff Upper Lip' can be summarized as having a STOIC attitude. This phrase is often used to describe someone who is able to remain calm and composed in difficult situations, even when faced with adversity. It implies that the person is able to maintain their composure and not show any emotion, even if they are feeling overwhelmed or stressed. The term is derived from the ancient Greek philosophy of Stoicism, which emphasizes the importance of self-control and resilience in the face of life's challenges.