Henry W. Fowler’s Dictionary of Modern English Usage, published in 1926, is still the greatest of all English grammar guides. The first edition or the lightly revised second edition (1965) is highly recommended.

Sprinkled among Fowler’s entries are topics that typify the author’s innovative approach to the study of grammar. His titles for these entries are often sly, with a soupçon of snark. Some examples: Sturdy Indefensibles, Presumptuous Word-Formation, Unequal Yokefellows, Pairs and Snares, Slipshod Extension.

That last topic is today’s focus, because slipshod extension may be more widespread nowadays than it was ninety years ago. The phrase refers to the maddening tendency of careless or ignorant speakers and writers to debase a word by overextending it beyond its proper meaning.

Calling a spider an insect is slipshod extension of the word insect: a spider is an arachnid. Calling a whale a fish is slipshod extension of the word fish: a whale is a marine mammal.

Here are a few of the countless other words that are susceptible to this lamentable practice:

Alibi  Be careful when you use alibi, originally a Latin word meaning “somewhere else.” When you say, “I have an alibi,” it means that you can prove you were elsewhere when the crime occurred. Fowler said of alibi: “That it should have come to be used as a pretentious synonym for excuse is a striking example of the harm that can be done by SLIPSHOD EXTENSION.”

Dilemma  The di in dilemma (like dichotomy or dioxide) indicates two: if you have a dilemma, it means you’re facing two tough choices. Do not use dilemma when all you mean is predicament. Fowler: “The word is a term of logic, meaning an argument that forces an opponent to choose between two alternatives both unfavourable to him: he is … on the horns of a dilemma, either of which will impale him.”

Literally  As all nitpickers know well and grow weary of saying, literally should be used only with the bare facts—no exaggerations, no analogies. Yet statements like They literally threw him under the bus show no sign of abating. What could be more slipshod than applying literally to an incident that literally never happened? Fowler: “Such false coin makes honest traffic in words impossible.”

Two revised editions of A Dictionary of Modern English Usage have been published in the last twenty years, but those in charge of editing these later versions have overruled many of Fowler’s traditionalist views and insights. In the process they have stifled one of the most distinctive and delightful voices in the field of linguistics.