Q. I've seen both "good-paying jobs" and "well-paying jobs" in the New York Times. Are the terms co-equal or has there been some ruling on the subject?

A. Looking through major newspapers for uses of "well-paying job" and "good-paying job," we find that the latter is the more common usage. This is surprising given that the adverbial use of good is often criticized, even though such use dates back to the 13th century. Moreover, good as an adverb is usually found in spoken English. It is likely that news writers have picked up "good-paying" from quoted interviews and speeches. The phrase is not grammatically incorrect, but it is bound to draw the attention of those who criticize do good and feel good. In formal edited writing, "well-paying" is your surest bet.

Q. Why do we call bullets rounds, as in "we shot 25 rounds apiece," or "this rifle holds 12 rounds"? Even my friends who use firearms are at a loss as to why this word is used.

A. Presumably the starting point for this sense of round is the older meaning "route or circuit," and hence, "a sequence of routine or repetitive actions" (as in "my round of daily chores" or "a round of drinks"). Since, in the early 18th century – when this usage seems to have arisen – loading and firing each charge of a cannon or musket involved a sequence of repetitive actions, it is not hard to see why one shot could have been referred to as a round. And from there it would have been natural to refer to the requisite amount of powder and projectile for one shot as itself a round. This usage would have continued into the 19th and 20th centuries, when repeating rifles and quick-firing cannon made the meaning of round more opaque.

Q. What is the opposite of a mistress (a woman who a man is cheating on his wife with)?

A. There is no established word in English referring exclusively to a married woman's male sexual partner outside the marriage. The noun paramour is sometimes used for one who enters into a romantic or sexual relationship not within the bounds of a marriage, and so sometimes can refer to a married woman's sexual partner outside the marriage. (It can also be used for a married man's female lover, which would make it synonymous with mistress.) Merriam-Webster's Collegiate Dictionary, Eleventh Edition defines paramour as "an illicit lover."