Longman Dictionary of Contemporary English - superlative

~1 adj 1 excellent  (a superlative performance) 2 a superlative adj or adv expresses the highest degree of a particular quality  (The superlative form of `good' is `best'.)  (- compare comparative1 (4)) ~2 n 1 the superlative the superlative form of an adjective or adverb  (`Biggest' is the superlative of `big'.) 2 a word in this form, used especially when expressing great praise or admiration  (a string of superlatives (=several superlative adjectives praising someone or something))