Frequency: The word is one of the 1500 most common words in English.
1.
Supreme is used in the title of a person or an official group to indicate that they are at the highest level in a particular organization or system.
MacArthur was Supreme Commander for the allied powers in the Pacific.
...the Supreme Court.
ADJ: ADJ n
2.
You use ~ to emphasize that a quality or thing is very great.
Her approval was of ~ importance...
ADJ emphasis
~ly
She gets on with her job and does it ~ly well.
ADV: ADV adj/adv