A reader has suggested that I take time out from exposing the purblind ignorance of that ass Simon Heffer and his ilk to identify some rules and distinctions of usage that are worth observing. 

H.W. Fowler had an entry, “sturdy indefensibles,” stock constructions like It’s me that violate some grammatical principle or other but which it is idle to object to. I continue to observe some distinctions that I can defend as precise and useful, and today I’ll share a dozen sturdy defensibles that I enforce almost daily in my editing.  If I had a dime for every one I’ve fixed, I’d be sitting on the porch drinking gin and reading murder mysteries instead of writing this blog post.

But first, remember your Bacon: “Reading maketh a full man; conference a ready man; and writing an exact man.” I am only talking about distinctions in writing for publication, not in conversation or informal writing. It suits me to talk pretty much the same way I write (or is it the reverse?), but that is not to everyone’s taste.

cement/concrete: Cement is a powder which, when mixed with water, sand, and stones, forms concrete. You are not standing on a cement floor; you are standing on a concrete floor.

consensus: A consensus is a general understanding or common judgment within a group. If you write consensus of opinion, I will get out the lopping blade.

cord/chord: A cord is a length of flexible material composed of strands woven or twisted together; a chord is two or more musical notes sounded at the same time. The two are most commonly confused when someone writes vocal chords. The vocal cords are the flaps of tissue, more properly called vocal folds, which vibrate to form speech or song when air is expelled. 

defuse/diffuse: A red-faced shouting match is an occasion on which you wish to defuse the situation, to make it less explosive, as you would by removing the fuse from a bomb. When something is diffused, it is spread out, losing its concentration, as dye diffuses in water. Metaphorically, a diffuse argument is wordy and ill-organized, failing to make its point aptly.

flack/flak: A flack is a public relations representative, a spokesperson, a mouthpiece, a stooge. (The overtones are not complimentary.) Flak is, literally, anti-aircraft fire; metaphorically, intense criticism, as if you were caught with sharp pieces of metal flying through the air at you at high velocity.

heroin/heroine: It should embarrass you if someone has to inform you that heroin is a drug and a heroine is a female protagonist.

imply/infer: Some people carelessly confuse the two, but the distinction in meaning is worth preserving. I tell my students that implying (suggesting, hinting) something is like putting a gift in a box and inferring (concluding) is like taking it out. If it helps, the root ply, from the Latin plicare, “to fold,” points to folding a meaning inside a sentence, and the root of infer, the Latin ferre, “to bring in,” suggests carrying the meaning into the open. (Etymology, however, is suggestive but not always conclusive.)

mantel/mantle: If you insist on writing about interior decor, you would do well to get it clear in your head that a mantel is a shelf above a fireplace. A mantle is a cloak, literally, or the role someone metaphorically assumes, as Elisha assumed the mantle of the prophet Elijah when the latter ascended into the heavens in a chariot of fire. 

rack/wrack: The rack was a medieval instrument of persuasion on which a crank stretched the body painfully. If you are racked with pain or feeling nerve-racked, then you feel as if you are being tortured. Wrack is wreckage, as when things go to wrack and ruin.

refute: To refute an argument or accusation is to prove it wrong, to demolish it conclusively. This is seldom accomplished to everyone’s satisfaction. If you want to indicate that someone disputes or denies an accusation, write that he or she rebuts it.

stable condition: The conditions of hospital patients are rated as good, fair, poor, and critical. “Stable” is not a condition, no matter how often a police report says so; “stable” is an indication that the patient’s previously announced condition is unchanged. If you insist on using the meaningless stable condition, I will excise it and leave it that the patient is receiving hospital treatment.

toxin: A toxin is a poisonous chemical, but not all poisonous chemicals are toxins. A toxin is a poison of biological origin, such as snake venom or the botox chemical produced from the bacterium Clostridium botulinum for cosmetic purposes.