Definitions:

1. Signifies a point of greatest importance, impact, or intensity. NOUN
   • The ultimacy of death hung heavy in the hearts of those who contemplated their mortality.
2. The highest or most important condition, truth, or authority. NOUN
   • Philosophers have long debated the ultimacy of moral values.
3. The state or quality of being ultimate, final, or most fundamental. NOUN
   • The concept of divine ultimacy lies at the heart of many religous doctrines.

Synonyms:

• absoluteness
• finality
• Supremacy