Noah Webster's Dictionary (n.) The state of being supreme, or in the highest station of power; highest or supreme authority or power; as, the supremacy of a king or a parliament.

Multi-Version Concordance Supremacy (1 Occurrence) Colossians 1:18 He is the head of the body, the assembly, who is the beginning, the firstborn from the dead; that in all things he might have the preeminence. (See NIV)