The extreme (e.g. highest, lowest, deepest, farthest, etc) extent or degree of something.

Exceptionally good; of the highest quality; superb. / (grammar) Of or relating to a superlative.

plural of superlative

In a superlative manner; in the greatest possible way.

The state or condition of being superlative.

plural of superlativeness

(obsolete) exaltation of anything beyond truth or propriety

plural of superlation

In Italian, Spanish, Portuguese, and Catalan: the form of an adjective formed by adding the suffixes -issimo, -ísimo, -íssimo, -érrimo, -imo, or -íssim to the adjective (with any final vowel dropped) to express a superlative that cannot be exceeded, having the sense “as ... as possible”.

(grammar) adverbial or adjectival forms modified by most or ending in -est, used when comparing three or more things