Definition

As an enslaved teenager in Baltimore in the 1830s, Frederick Douglass kept hearing about something called "abolition"—a word whose meaning he did not know. "If a slave killed his master, set fire to a barn, or did anything very wrong in the mind of a slaveholder," he observed, "it was spoken of as the fruit of abolition. Hearing the word in this connection very often, I set about learning what it meant." He looked up abolition in a dictionary and found the definition:

abolition. n.s.: The act of abolishing.¹

Though technically unimpeachable, this definition was not helpful to Douglass. "Here I was perplexed," he noted drily some decades later, for "it left me in ignorance at the very point where I most wanted information—and that was, as to the thing to be abolished." When he eventually did learn the meaning of abolition, it was not from a definition but from context: he read a newspaper article advocating the "abolition of slavery" and realized that this was the "abolition" in question. Thus, Douglass pointedly observed, the newspaper "gave me the incendiary information denied me by the dictionary."²

Douglass was evidently familiar with the norm that if you don't know what a word means, you should look up its definition in a dictionary. This is far from the only imaginable strategy for learning the meanings of words, and as Douglass's experience illustrates, it's not always an effective one. Douglass doesn't specify how he learned to expect a dictionary to disclose the meaning of an unfamiliar word—but I acquired the same expectation, and I know where I learned it: it was taught to me in grade school, implicitly as well as overtly, and at least once in song. "Oh, the dic-dic-dictionary / is very necessary," trilled an old LP that played repeatedly in a classroom of my early childhood:

Imaginary or contrary,       any old word you've seen,estuary, dromedary:       find out what they mean.³

The lyrics make a dictionary out as a kind of key that can unlock hidden realms of knowledge. "Look inside if you've a mind / to learn the answers first," the song continues, rising to the preposterous conclusion that "it's the perfect book, you'll find, / to quench your mental thirst."⁴ Although I doubt very much that a dictionary has ever been the perfect book to quench any child's mental thirst, it is true that there are circumstances under which a choice definition can help you understand something you didn't understand before.

But the lexicographical promise to help you understand coexists awkwardly with the overwhelming tendency of dictionary definitions to be at least as obscure as the words they ostensibly illuminate. Douglass was not the first to discover this irony. Already by the 1780s, Samuel Johnson's definition of the word network was proverbial for its un-helpfulness: "Any thing reticulated or decussated, at equal distances, with interstices between the intersections."⁵ The rhetoric of definitions is distinctive and peculiar, often involving the words "that which …," "one who …," "the quality or state of …," "belonging to or resembling …," and especially "of or pertaining to. …" Etymologically speaking, a definition is not an opening of meaning but a closing-off: a bounding, a hemming-in, a delimiting, a conferring of the "finitude" at the word's center. Ambrose Bierce would parody the self-obfuscating tendency of dictionary definitions in thirty years' worth of newspaper columns that he later compiled into The Devil's Dictionary (1911):

eat, v. i. To perform successively (and successfully) the functions of mastication, humectation, and deglutition.⁶

Unlike a gloss, which is tasked with getting you close enough to a word's meaning that you can understand it, a definition is tasked with circumscribing that meaning and showing where it begins and ends, like a fence or hedgerow.

The worth of doing this is not obvious unless you have been educated to value it—for example, via a recorded voice insisting in chorus after chorus that "the dic-dic-dictionary / is very necessary." When the psychologist A. R. Luria wanted Soviet peasants...