The term 'supremely courageous' can be summarized as HEROIC, which is a 6-letter word. This term is often used to describe someone who has shown great courage and bravery in the face of danger or adversity. It is usually associated with acts of selflessness and heroism, such as risking one's life to save another. This term is often used to honor those who have gone above and beyond the call of duty in order to help others.