The term 'Supreme Deity' is often used to refer to a GOD or gods in various religions. The crossword solution for this term is 'GOD, ' which is a three-letter word. This is a common name for the highest deity in many monotheistic religions, such as Christianity, Judaism, and Islam. In polytheistic religions, such as Hinduism, the term 'Supreme Deity' can refer to a single GOD who is the most powerful among many gods.