IPA: /ˈʌltɪməsi/
KK: /ˈʌltɪməsi/
The state or quality of being the final or most important in a series or process.
The ultimacy of her decision left no room for further discussion.
Ultimacy → It is formed from "ultimus" (meaning last or final) and the suffix "-cy" (meaning the state or condition of). The word "ultimacy" refers to the state of being the last or final in a series or process.
Think of 'last' ('ultimus') to remember that 'ultimacy' means the state of being final or last.
No commonly confused words.