Meaning of “ultimate” - Learner’s Dictionary

ultimate

adjective [ always before noun ] uk us /ˈʌltɪmət/
BEST

B2 better, worse, or greater than all similar things:

Climbing Mount Everest is the ultimate challenge.
the ultimate insult
FINAL

final or most important:

the ultimate aim/solution

(Definition of “ultimate adjective” from the Cambridge Learner’s Dictionary © Cambridge University Press)