The following words are especially susceptible to misuse. If you spot any of them in a deranged condition, consider them infectious and stay out of their way.
abjure (renounce) / adjure (entreat)
Try this mnemonic to remember which is which:
The Deacon adjured us to abjure Bacchanals.
This does not mean "energize." Quite the opposite.
Although immensity falls within the official definition of the word, academic types restrict the use of enormity to mean wickedness or atrocity, and assume any other usage is wrong. According to that school of thought, the Holocaust was an enormity but the universe is not. If you use the word merely to imply that something is big, expect to be accused of bad English. When size is the topic, Merriam-Webster recommends using enormity in the sense of something whose scale is overwhelming. In that sense, someone starting a teaching career can suddenly realize the enormity of the responsibility involved; a stranded traveler who must hike to the nearest phone to summon help confronts the enormity of the desert. See Merriam-Webster's helpful explanation.
turbid (obscure or muddy) / turgid (swollen or distended)
Both are sometimes confused with turbulent in watery metaphors. A turgid river is swollen; a turbid one is full of sediment; a turbulent one is going every whichway fast. (A flooding river can be all three, but for different reasons.) Turgid and turbid are often applied to prose. This mnemonic might help you remember when to use which : associate turGid with swollen Glands and inflated or pompous verbiage; associate turBid with a muddy Bog and murky or unclear reasoning.
Many people seem to think this is a fancy way of saying "vouch for" or "guarantee," as in "I cannot vouchsafe that all these links are current." Beware.
If any of the above entries describe your use of a word (you don't have to admit anything), please give a close read to its definition in the Merriam Webster World Wide Webster Dictionary, or in the Hypertext Webster Gateway. Follow the links in the Megalist.