Libraries, those magnificent repositories of knowledge, are brimming with words of all sorts: written, spoken, sung, and projected. This is natural since, since the word, “a single unit of written or spoken language,” is mankind’s primary vehicle for sharing information. “Word” an extremely old term, coming from that most ancient of languages, the Proto-Indo-European term “were-,”meaning “speak, say.” Words themselves are made up of “morphemes,” which the Macmillan Dictionary defines as “the smallest unit of meaning in a language. A morpheme can be a whole word, for example ‘the,’ or part of a word, for example ‘un’ in ‘unable.’” Prefixes, suffixes and rootwords are all morphemes, and a writer’s ability to combine them defines his skill-level.

Not everyone agrees on what words are proper to use. Apart from naughty, ugly, and vulgar expressions, there are the unusual, “high-falluting,” terms that are often exquisitely specific, and there are the plain, unadorned, and widely comprehensible words.

C.S. Lewis, author of “The Lion, the Witch, and the Wardrobe,” earnestly urged aspiring writers to “try to use language so as to make quite clear what you mean and make sure [your] sentence couldn’t mean anything else.” The best way to accomplish that, according to Lewis, is to [a]lways prefer the plain, direct word to the long, vague one. Don’t ‘implement’ promises, but ‘keep’ them.”

Other, sometimes greater, authors, prefer a more expansive palette of expression. For example, consider Patrick O’Brian, my favorite wordsmith. I admire the rich variety of O’Brian’s vocabulary nearly as much as his ability to write so compellingly, sweeping my imagination along. However, keeping a good dictionary nearby is a good idea when reading his work. I used to log his unusual words and brilliant turns of phrase on the back fly-pages of his novels. Among the dozens I recorded while reading “The Hundred Days,” the nineteenth in his twenty-volume magnum opus, the Aubrey-Maturin series, “bashi-bazouks” (“one of a group of irregular Turkish soldiers notorious for their brutality), “stertorious” (from “stertor,” Latin for deep, heavy snoring), “sett” (badger hole), “surds” (expressions containing one or more irrational roots of numbers), and “shawm” (a medieval form of oboe). O’Brian’s use of these lesser-known expressions is playful rather than showy, making for humorous reading instead of plodding drudgery.

Sometimes tiny words, like “etc.,” “re,” and “sic,” can carry powerful messages, too. “Etc.” is the abbreviation of the Latin “et cetera,” literally “and the others.” Its use began in the early 1400s and was originally spelled “&c.” “Re” comes from the Latin phrase “in re,” which means “in the matter of” or “concerning.” These days “re” is used so often for “regarding” that it’s gained that meaning, too in many dictionaries.

“Sic” means “that’s how it really appears in the original,” and in Latin it means “thus.” Sic in brackets is used to indicate that the wrong thing you’re writing was written that way in the source you’re quoting. In one of these columns long ago, I included a quotation that quoted a second person who made a mistake, and the original writer included a [sic] after the error to show readers the error wasn’t his. Unfortunately, my column’s editor didn’t know about [sic], changed it to “sick,” and dropped the quotation marks, so it read as if I was calling the original quotation sick.

We laugh about it now, but perhaps with a trace of bitterness. Some words are actually intended for humor, like the expressions defined in Mort Walker’s “Lexicon Comicana.” Walker’s the creator of the Beetle Baily comic strip, and in the 50s he started defining some of the unnamed elements of comic strip communication. When a comic strip character is stressed or working hard, big sweat drops fly from their head, and Walker termed these “plewds.” “Emanata,” by comparison, are the straight lines coming out of the head to indicate shock. And those profanities spelled “#@$#!” are “grawlixes.” Walker coined these as a lark, but they’ve since “acquired an unexpected validity” among cartoonists and have entered the English language.

It’s like that master of written communication, Mark Twain wrote, “The difference between the right word and the almost right word is the difference between lightning and a lightning bug.”