The term 'Supreme Leader' is a title given to a person who holds the highest position of power in a particular country or organization. DIANA (5 letters) is a female given name derived from the Greek goddess of the hunt, DIANA. Ross (4 letters) is a Scottish surname derived from the Gaelic word for headland. ESS (3 letters) is an acronym for Emergency Support Services, which provides assistance to people affected by disasters. TSAR (4 letters) is a title used by Slavic monarchs and emperors, derived from the Latin word Caesar. Dianaross (9 letters) is a combination of the two names DIANA and Ross. Therefore, the crossword solutions for the term Supreme Leader are DIANA, Ross, ESS, TSAR, and Dianaross.