Q. What is the term used for a word when spelled forward has one meaning and when spelled backwards has another meaning: for example, Desserts/Stressed?

A. The term you're thinking of is semordnilap, which is actually the word palindromes spelled backwards.

Q. My friend and I thought that since nonchalant is a word in the dictionary, perhaps the word chalant means the opposite of nonchalant, maybe "concerned." What do you think?

A. There is some evidence for the use of chalant as an adjective meaning the opposite of nonchalant. Generally it is used in a humorous fashion and with the intention of drawing attention to itself. It is what we refer to as a back-formation (a word formed by subtraction of a real or supposed affix from an already existing longer word). A similar back-formation often used for humorous effect involves the use of plussed as the opposite of nonplussed.

Sometimes these back-formations go beyond the status of humorous words and become standard parts of the English language. An example of this is kempt which appears in our Collegiate Dictionary and is the result of a back-formation from unkempt.

While chalant isn't entered in any major dictionary, it could be said to be a legitimate word. Like many back-formations, its meaning is easily sorted out—most English speakers familiar with nonchalant are likely to recognize and understand chalant. And if its usage becomes frequent enough, we could consider it for inclusion in one of our dictionaries.

Q. Is there a preference for "champing at the bit," or should a person "chomp at the bit"?

A. The earlier verb was champ, making its written debut in the 16th century and meaning "to bite, to gnash, to grind with one's teeth." It's still in use, though nowadays it appears almost exclusively in the phrase "champ at the bit." The verb chomp made its appearance in the late 16th century, and was clearly an alteration of "champ," sharing almost all of champ's meanings.

"Champ at the bit" was used before "chomp at the bit" and it has enjoyed a nice, long reign. However, popular usage has been swinging towards "chomp at the bit" since it first began being used in the phrase, sometime around the beginning of the 20th century. In fact, our evidence indicates that "chomping at the bit" is used in recent print sources more frequently than "champ at the bit," so we can't possibly ignore it.