(1) Tending to remain calm. (2) Free from harsh changes or extreme variation.

*Equable* usually describes either climate or personality. The word seems to be used less today than in decades past, maybe because the personality type is less admired than it used to be. A steady, calm, equable personality may not produce much excitement but usually makes for a good worker and a good parent, and maybe even a longer life. In the words of the poet Robert Service: “Avoid extremes: be moderate / In saving and in spending. / An equable and easy gait / Will win an easy ending.”

Being equal to some need or requirement.

When we question the adequacy of health-care coverage, or parking facilities, or school funding, we're asking if they are *equal* to our need. The adjective *adequate* means “enough” or “acceptable”—though in sentences like “His performance was adequate,” it really means “no better than acceptable.”

(1) A state in which opposing forces are balanced so that one is not stronger or greater than the other. (2) A state of emotional balance or calmness.

*Equilibrium* contains a root from the Latin *libra*, meaning “weight” or “balance.” As a constellation, zodiac symbol, and astrological sign, Libra is usually pictured as a set of balance scales, often held by the blindfolded goddess of justice, which symbolizes fairness, equality, and justice. *Equilibrium* has special meanings in biology, chemistry, physics, and economics, but in all of them it refers to the balance of competing influences.

A day when day and night are the same length.

If you know that *nox* means “night” in Latin, it's not hard to remember the meaning of *equinox*. There are two equinoxes in the year: the spring equinox, around March 21, and the fall equinox, around September 23. The equinoxes are contrasted with the *solstices*, when the sun is farthest north and south of the equator. The summer solstice occurs around June 22 (the longest day of the year), the winter solstice around December 22 (the shortest day).

A questioning or examining that is often harsh or severe.

While an *inquiry* can be almost any search for truth, the related word *inquisition* suggests a long, thorough investigation that involves extensive and harsh questioning. Though the two words originally had about the same meaning, today *inquisition* tends to remind us of the Spanish Inquisition, an ongoing trial conducted by church-appointed *inquisitors* that began in the Middle Ages and sought out nonbelievers, Jews, and Muslims, thousands of whom were sentenced to torture and to burning at the stake.

(1) A privilege or profit that is provided in addition to one's base salary. (2) Something claimed as an exclusive possession or right.

Though the Latin source of *perquisite* originally meant “something insistently asked for,” the “ask” meaning has mostly vanished from the English word. A perquisite, often called simply a *perk,* is instead something of value that the holder of a particular job or position is entitled to, usually without even asking. The President of the United States, for instance, enjoys as perquisites the use of Camp David and Air Force One. Perhaps because perquisites are usually available to only a small number of people, the word sometimes refers to non-job-related privileges that are claimed as exclusive rights.

Eager to acquire; greedy.

Unlike most tribal peoples and the populations of some older countries, we Americans live in an acquisitive society, a society devoted to getting and spending. And America often makes successfully acquisitive people into heroes; even Ebenezer Scrooge, that model of miserly greed and *acquisitiveness*, was once defended by a White House chief of staff. An acquisitive nation may seek to *acquire* other territories by force. But mental *acquisition* of specialized knowledge or skills—or new vocabulary!—doesn't deprive others of the same information.

A demand or request (such as for supplies) made with proper authority.

*Requisition* was originally a noun but is now probably more common as a verb. So we either can speak of sending our office's purchasing department a requisition for computers, or of *requisitioning* more computers from the department. The word has an official sound to it. However, one of Hollywood's bittersweet love stories begins when Omar Sharif, playing a World War II freedom fighter, says to Ingrid Bergman, who is the owner of a stately old yellow Rolls Royce, “I've come to requisition your car.”