What is another word for "unprecedented"?

Roget's Thesaurus (1911) lists these synonyms for "unprecedented": all, almost, and, another, bear, between, blue, cast, chalk, cheese, class, creativeness, daisy, diamond, differ, difference, different, disparate, disparity, dissemblance, dissimilar, dissimilarity, divergence, divergent, diversified, diversify, diversity, dock, ever, experience, far, father, few, fewness, for, from, hardly, has, infrequency, infrequent.