M is for "The Devil's Dictionary" (No. 152 in a series)

The Devil's Dictionary is a satirical dictionary written by Ambrose Bierce (1842-c.1914, caricatured above by David Levine). Bierce was an American author who began the book as a newspaper serial. First published in 1906 as The Cynic's Word Book, it was retitled in 1911, using the name we know it by today, which is the title that Bierce preferred. Some of the definitions have not aged all that well, but many have.

MAD, adj. Affected with a high degree of intellectual independence; not conforming to standards of thought, speech and action derived by the conformants from study of themselves; at odds with the majority; in short, unusual. It is noteworthy that persons are pronounced mad by officials destitute of evidence that themselves are sane. For illustration, this present (and illustrious) lexicographer is no firmer in the faith of his own sanity than is any inmate of any madhouse in the land; yet for aught he knows to the contrary, instead of the lofty occupation that seems to him to be engaging his powers he may really be beating his hands against the window bars of an asylum and declaring himself Noah Webster, to the innocent delight of many thoughtless spectators.