Ultimate shares its deepest root with the word else — both descend from a Proto-Indo-European root meaning 'beyond'. Latin took that root and built ultimus, the superlative form meaning 'the farthest' or 'the last'. From there came ultimare, 'to bring to an end', whose past participle ultimatus gave English its word in the 1650s. For its first century in the language, ultimate meant strictly 'final in a sequence' — the ultimate cause, the ultimate destination. The grander sense of 'supreme' or 'the best achievable' crept in during the 1700s, and by the twentieth century advertisers had seized it entirely, applying 'ultimate' to everything from cars to sandwiches. Its sibling ultimatum retains the older gravity: a final diplomatic demand, issued when all other options have been exhausted. Penultimate, meanwhile, adds the Latin paene ('almost') — the one just before the last.