Majuscule looks like the complement to minuscule, and the resemblance is no coincidence. Minuscule appeared in the early 18th century as a word for a lowercase letter, then later as the word for certain ancient and medieval writing styles which had "small forms." Minuscule then acquired a more general adjectival use for anything very small. Majuscule is the counterpart to minuscule when it comes to letters, but it never developed a broader sense (despite the fact that its Latin ancestor majusculus has the broad meaning "rather large"). The adjective majuscule also exists, as does its synonym majuscular. Not surprisingly, the adjectives share the noun's specificity, referring only to large letters or to a style using such letters.
Word History
Etymology
French, from Latin majusculus rather large, diminutive of major