SIR: I was discussing bad dreams with a friend when I suddenly wondered why we refer to them as nightmares. "Night" generally means those hours between dusk and dawn, and "mare" generally means a female horse. How did we get these two words to refer to a bad dream? - William S.

ANSWER: The key to this puzzle is that the "mare" in "nightmare" has nothing to do with a female horse. It comes from an Anglo-Saxon word meaning an evil spirit that sits, lies or dances on your chest during sleep. In short, this "mare" rides you instead of vice versa. No wonder you have bad dreams.SIR: During a recent visit to my company's headquarters, I remarked that my ancestry is part Scotch and part German. Immediately, my boss informed me that the liquor is scotch but the people are Scottish. Was I incorrect, or was my boss being a bit pompous? - Ron B.

ANSWER: I choose not to answer the last half of that question. As for the first half, this is an old controversy, and you were incorrect in the minds of those people in or from Scotland (note how I avoided the issue) who believe they should be called Scottish or Scots. Otherwise, don't worry.

SIR: I read a statement that people who were big borrowers are now getting their "just deserts." Of course, the phrase should be "just desserts." Shouldn't it? - S.L.C.

ANSWER: Not at all. "Just deserts" is right, hard as it may be for many to believe. There are two nouns spelled alike ("desert") but pronounced differently and with different meanings - DES-ert, meaning a barren and desolate place, and deSURT, meaning what is deserved.

SIR: Can "crass" mean avaricious, greedy, money-hungry? I read and hear it used that way, but my dictionary limits its meaning to insensitive and stupid - Richard G.

ANSWER: Well, let's see. If crass means coarse, unfeeling and stupid, which it does, I suppose you could say at least some greedy people are crass. But it is stretching things a bit to say they all are, isn't it? It's bad enough to be crass without also being accused of greediness in one breath.

PUZZLED QUESTION of the week, from A.W.:

"I read something from a company that offers `semi-driver training.' Do they train drivers to be less than adequate?"

Send questions, comments, and good and bad examples to Lydel Sims, Watch Your Language, P.O. Box 161280, Memphis, TN 38186. If you quote a book, please give author, title and page number. Sorry, but questions can be answered only through this column.