Q I know that to ostracize someone means to banish or exclude that person from a place or group. Recently I learned that the word “ostracize” shares a similar root as the word “oyster.” How are the two words related? – K.O., Warwick, R.I.

A: In ancient Greece, prominent citizens whose power or influence threatened the stability of the state could be exiled by a practice called ostracism. During annual elections held in Athens, voters could elect to banish another citizen by writing that citizen’s name down on a potsherd (a fragment of earthenware or tile). Citizens who received the required number of votes (usually a majority of at least six thousand) would then be subject to temporary exile from the state (usually for 10 years). The Greek word “ostrakon” referred to the shell used in this voting process and was related to “ostreon,” the word for “oyster,” which has a rough, irregular shell. “Ostrakon” begat the verb “ostrakizein,” meaning “to banish by voting with potsherds,” the direct ancestor to our “ostracize.”

When the word “ostracism” first appeared in English in the 16th century, it was used only to refer to the old Athenian custom. The word is now used to refer to any kind of banishment from a group, usually inflicted on a social level.

Q I came across the word “jeopard” in an old book recently. Is this a misspelling or a typo intended to be “jeopardize”? – A.K., Baltimore, Md.

A: No, it’s a legitimate word in its own right.

It may be hard for you (or any modern reader) to believe that that “jeopardize” was once controversial, but in 1870 the grammarian Richard Grant White called it “a foolish and intolerable word.” His view was shared by many 19th-century American critics. The preferred verb was the one you’ve noted – “jeopard,” a much older word that first appeared in print in the 14th century, but that had fallen into disuse by the 1600s. (The upstart “jeopardize” first turned up in 1582, but grammarians still hadn’t acknowledged it as an acceptable word 300 years later.) In 1828, Noah Webster himself declared “jeopardize” to be “a modern word, used by respectable writers in America, but synonymous with ‘jeopard,’ and therefore useless.”

Useless or not, “jeopardize” became increasingly common in both America and Great Britain, as attempts to resurrect “jeopard” met with predictable failure. In fact, the primarily American protests against “jeopardize” began to die down by 1900, and it has now been about a hundred years since anyone has raised any serious objections to its use. “Jeopard,” on the other hand, is now used only in recalling the language of the past.

Incidentally, these words derive ultimately from the Anglo-French noun “jeuparti,” which means “alternative” or, literally, “divided game.”

Q My brother just got a job at one of those big theme parks in Florida. They recently closed the park to all but the employees, who brought their families for an annual picnic and free use of the park for the day. It sounded like fun to me, but my brother sounded less than thrilled when he called it a “busman’s holiday.” Can you explain what he meant?

A: Put yourself in your brother’s shoes – he had to work on his day off! This is a good example of “busman’s holiday,” or a day off from work spent in following or observing the practice of one’s usual occupation. Often a day off is a “busman’s holiday” by choice, because some people are workaholics who enjoy nothing better than the practice of their profession. For those like your brother, however, it may not be a holiday at all.

“Busman’s holiday” was first recorded in 1893. There are several unsubstantiated explanations of its origin, most of which are variations on a theory linking it to busmen in London during the 19th and early 20th centuries.

These were, of course, drivers of horse-drawn vehicles used for public transportation. The popular story goes that the busmen often became emotionally attached to the team of horses that drew their buses. Many a busman apparently feared that his team would miss him on his day off. If he suspected that the substitute drivers would not give his horses the proper amount of tender loving care, he might remain on board throughout the journey to look after his team. The busman would thus spend his holiday on the job. A simpler explanation is that since the job of a busman involved traveling, going on a traveling holiday was for a busman not all that different from working.

Q We’re hearing a lot these days about “mentoring” programs. Where does the “mentor” come from? – R.B., Longview, Texas

A: “Mentor” is the name of a character in Homer’s “Odyssey” who serves as the advisor of young Telemachus, the son of Odysseus. A wise and trusted counselor, Mentor is especially helpful because much of the time he is actually the goddess Athena, who assumes Mentor’s identity in order to give Telemachus advice and information.

Today, the word “mentor” is applied to a senior person, often in an organization, who assists less-experienced and usually younger persons to succeed. The concept is so familiar that, as you’ve noted, it has turned into a verb.

This column was prepared by the editors of Merriam-Webster’s Collegiate Dictionary, Tenth Edition. Readers may send questions to Merriam-Webster’s Wordwatch, P.O. Box 281, 47 Federal St., Springfield, MA 01102.