Nouns

(n)ultimatethe finest or most superior quality of its kind“the ultimate in luxury”

Adjectives

(a)ultimatefurthest or highest in degree or order; utmost or extreme“the ultimate achievement”, “the ultimate question”, “man's ultimate destiny”, “the ultimate insult”, “one's ultimate goal in life”
(s)ultimatebeing the last or concluding element of a series“the ultimate sonata of that opus”, “a distinction between the verb and noun senses of `conflict' is that in the verb the stress is on the ultimate (or last) syllable”