Supreme, a.
Etymology: [L. supremus, superlative of superus that is above, upper, fr. super above: cf. F. suprême. See Super-, and cf. Sum.]
1. Highest in authority; holding the highest place in authority, government, or power. He that is the supreme King of kings. Shak.
2. Highest; greatest; most excellent or most extreme; utmost; greatist possible (sometimes in a bad sense); as, supreme love; supreme glory; supreme magnanimity; supreme folly. Each would be supreme within its own sphere, and those spheres could not but clash. De Quincey.
3. (Bot.)
Situated at the highest part or point. The Supreme, the Almighty; God.
Shades of meaning
Fernald has no entry of its own for supreme; he lists it under absolute.
Where he writes about it:
In the strict sense, absolute, free from all limitation or control, and supreme, superior to all, can not properly be said of any being except the divine. — from absolute
Both words are used, however, in a modified sense, of human authorities; absolute then signifying free from limitation by other authority, and supreme exalted over all other; as, an absolute monarch, the supreme court. — from absolute