As an added bit if trivia fun, each of the "Good form" examples below is taken from a piece of classic literature. How many can you name without using Google? Each of the "Bad form" examples are true, in-the-wild examples that I've found on blogs. (Ah, the benefits of editing.) And I've been really mean by including a link to the misuse.
EnervatedAlthough the word enervated looks like it might give you energy and nerve, it in fact does just the opposite. A person is enervated when he loses his nerve, or when he is weakened.
Bad form: "Why is it that if I were at GenCon and had not slept and rested the same way I'd feel enervated and ready to go for the convention?" link
Good form: "But why do men degenerate ever? What makes families run out? What is the nature of the luxury which enervates and destroys nations? Are we sure that there is none of it in our own lives?"
EnormityAlthough some people insist that enormity always refers to great wickedness, great writers have been using it in a wider sense for ages. Enormity does not, however, simply mean "very large." Along with (often figurative) size comes a sense of importance or of monstrosity: the enormity of the AIDS epidemic in Africa; the enormity of Nazi crimes against the Jews.
However, if you use enormity to mean anything other than "great wickedness" (e.g., the enormity of James Earl Ray's actions), a lot of people won't like it and will challenge you on it. Be prepared to defend yourself.
Bad form: "The enormity of the planet and relatively small numbers of humans in early historic times lessened the global impact of hunter gatherer land management practices . . .
Good form: "I wish my people to be impressed with the enormity of the crime, the determination to punish it, and the hopelessness of escape."
EntitledThis one bugs me because it is misused so often and so badly. Movies are not entitled. Books are not entitled. TV shows are not entitled. They are simply titled. People who purchase a ticket are entitled to see the show. People who earn their driver's licenses are entitled to operate automobiles. Ignorant, uneducated, dilettante daughters of millionaires feel entitled to party all night, every night. To be entitled means to have grounds for claiming or doing something.
(To be fair, there are those who believe it's perfectly fine to use entitled to mean titled because it has been misused so often as to become acceptable. To that I say bollocks. Regardless, you'll make your editor and your readers happier by differentiating between titled and entitled this way.)
Bad form: "I was now about twelve years old, and the thought of being a slave for life began to bear heavily upon my heart. Just about this time, I got hold of a book entitled The Columbian Orator." (It's lasting writing like this that gives the entitled = titled argument some teeth. This is from Narrative of the Life of Frederick Douglass.)
Good form: "[I]t hath been said that, not being concerned in the taking the thief, he could not have been entitled to any part of the reward if he had been convicted . . . "
Grizzly/GrislySomething that's grisly is horrifying or inspires disgust. Because it's a homophone, it's often mistaken for the grizzly in grizzly bear. And because of that mistake, some people believe that a grizzly bear is so named because it is the meanest type of bear, or most likely to attack, or just the ugliest. That isn't true. Like the brown bear and the black bear, the grizzly bear is named after its color. Grizzly, or grizzled, means streaked or dotted with gray.
Bad form: "Looking every bit like a sexy grisly bear, Hugh Jackman picked up his daughter from school in New York, New York on Thursday, January 6th, 2010." link
Good form: "It was a grisly thing, this light touch from this noiseless and invisible presence; it made the boy sick with ghostly fears."
LatterIf you think that latter means "the last option in a list," you're only partly right. Latter is specifically the second choice out of two -- the opposite of former. Latter and last follow the same pattern as better and best, younger and youngest, and elder and eldest.
It can also mean "of a later time period," as with the Church of Latter-Day Saints.
Bad form: "The tablet, which is now available only in Japan, presents itself in 3 variants- 10 inches (pictured below), as well as a 7-inch version and a 4-inch device. The latter of the three new tablets is a bit similar to a smartphone." link
Good form: "Judith was a girl of quick sensibilities and of impetuous feelings; and . . . she sometimes betrayed the latter with a feeling that was so purely natural as to place it as far above the wiles of coquetry as it was superior to its heartlessness."
LimpidEven though this word is 66% limp, it has nothing to do with limpness. Limpid means physically clear (like a mountain stream) or in a clear and simple style (like a Shel Silverstein poem). It can also mean serene. It's related to the word lymph, which comes from the Latin word for water.
Bad form: "She was sweaty and pale, her long, curly black hair damp and limpid." link
Good form: "[The river] flowed noiselessly, swift, and cold to the eye; long, thin grasses huddled together in it as the current drove them, and spread themselves upon the limpid water like streaming hair . . . "
MeretriciousMeretricious can be used in a few different ways, and none of them are positive. Something that is meretricious is plausible, but only in a superficial way. Saying that we can fight international terrorism by murdering all Muslims is a meretricious (and odious) argument.
Meretricious can also mean alluring in a superficial or showy way. Some have argued that the movie Avatar was meretricious because people were taken in by the lush alien landscapes, the high-tech 3D, and the supposed epic scope of the drama, in spite of the fact that the story is really just a mashup of Pocohontas and the Smurfs.
And finally, meretricious can mean "of or relating to prostitution or prostitutes."
Meretricious is NOT the adjective form of merit. You want meritorious instead.
Bad form: "Don received a meretricious service award having served in The Ordnances Gaze Frestal 1966-1969 in Germany." link
Good form: "There is nothing showy or meretricious about the man. He believes in mineral paint, and he puts his heart and soul into it."
NoisomeNoisome isn't about noise. It means obnoxious or objectionable to the senses, especially the sense of smell. It's a synonym of noxious and malodorous, not cacophonous or dissonant. It's related to annoy.
Bad form: "Sasch BBC presents a playful anthem, interlaced by elements of noisome percussion and luxuriant atmospheric chords." link
Good form: ". . . as the Yahoos were the most filthy, noisome, and deformed animals which nature ever produced, so they were the most restive and indocible, mischievous and malicious . . . "
OdiousNot a synonym for noisome, odious has nothing to do with odors. It means evil, vile, deserving of hatred. Odious turns into odium as a noun.
Bad form: "The carpet still lingers in some distant odious past, fresh whiffs of the good old days occasionally assaulting my nose. I billed the landlord for two bottles of Febreze, and intend on purchasing another." link
Good form: "She had no tolerance for scenes which were not of her own making, and it was odious to her that her husband should make a show of himself before the servants."
SpendthriftThis one always throws me because it's an oxymoron. If a person is a spendthrift, he isn't thrifty; he spends his money wastefully. (And just because I'm blogging about it here doesn't mean that I'll remember the next time the possibility of using this word comes up. Thank goodness for dictionaries.)
Bad form: "Constitutionally, I'm a bit spendthrift. I'll splurge on sushi and have an affinity for sneakers (euphemisms), but do my apparel shopping almost exclusively at thrift stores. I use coupons religiously . . ." link
Good form: "I paid three pennies for my breakfast, and a most extravagant price it was, too, seeing that one could have breakfasted a dozen persons for that money; but I was feeling good by this time, and I had always been a kind of spendthrift anyway . . . "
WizenedAlthough wizened looks like a description for a wise vizier, it actually has nothing to do with either wisdom or wizardry. If something is wizened, it's dry and wrinkled with age. Granted, as someone ages and becomes more wizened, one hopes that they also become wiser, but the two aren't etymologically linked.
Bad form: "After a couple years of these type of individuals I have grown wiser, and it has been a very, very frustrating journey. So, here I am, (understatement) cynical, very cynical but smart and wizened to bullshit, and avoiding it." link
Good form: "The wind was so nipping that the ivy-leaves had become wizened and gray, each tapping incessantly upon its neighbour with a disquieting stir of her nerves."