A deep regret arising from a sense of guilt for past wrongs.

In Latin, *mordere* means “to bite” ; thus, remorse is something that “gnaws” at you over and over. In criminal court, judges are always looking for signs that a convicted felon is suffering remorse for his crime; if not, the judge may well lengthen his sentence or deny him parole after serving part of it. Remorse is stronger than mere regret; real remorse is the kind of thing that may last a lifetime.

To state or do over again or repeatedly.

In Latin, *iterum* means “again,” so *reiterate* has the basic meaning of “repeat over and over.” Our word *iteration* is used a lot by computer programmers today, often meaning a repeated response to program instructions that gets something closer to its final form, but also often meaning a new version of something, such as a program. But a *reiteration* is simply a repeat or several repeats.

To make young or youthful again; to give new vigor to.

*Juvenis*, Latin for “young,” can be seen in a word such as *juvenile*. *Rejuvenation* is something that can be carried out on a creaky old house, a clunker of a car, a sluggish career, a weak economy, or a company that's lost its edge, but *rejuvenate* and *rejuvenation* are probably used most often for talking about our physical selves. Ads for lotions promise skin rejuvenation; diet-book covers show rejuvenated (or maybe just young) models bursting with health. We still seem to be searching for that “Fuente de la Juventud” that Juan Ponce de León failed to discover five hundred years ago.

(1) To make agree. (2) To make friendly again.

In Latin, *conciliare* means “to calm, soothe” ; thus, *reconcile* means essentially “to calm again.” Warring friends can often be reconciled by a nice note or apology. When you're faced with two things that don't square very well, you may have to reconcile them, the way a scientist might try to reconcile the differing results from two research projects. The U.S. House and Senate, in a process called *reconciliation*, try to produce one final bill from two different versions that they've passed separately. To reconcile yourself to something means to get used to it; thus, you may need to reconcile yourself to not getting to the beach next summer, or you may have reconciled yourself to the idea of your daughter in the Peace Corps marrying a Mongolian goat herder.

(1) Done, given, or felt equally by both sides. (2) Related to each other in such a way that one completes the other or is the equal of the other.

In Latin, *reciprocus* means “returning the same way” or “alternating.” So in a *reciprocating engine*, like the one in your car, the pistons move back and forth, and that motion is transformed into the rotary motion of the crankshaft. A *reciprocal* is a pair of numbers (such as 5/6 and 6/5) that can be multiplied to produce 1. *Reciprocity* (with the accent on the third syllable) between two nations means they agree to recognize certain things granted in one country as being valid in the other—for example, your driver's license.

(1) To oppose by argument. (2) To prove to be wrong.

The *-but* in *rebut* once meant basically “butt,” so *rebut*'s original meanings were “to drive or beat back” and “to attack with violent language.” *Rebuttals* can still be rather violent, as anyone who has watched some heated moments in a presidential debate can testify. The word is often used by lawyers, since the lawyer for the accused or for the party being sued almost always tries to rebut the charges against his or her client; but it's also used in plenty of contexts outside the courtroom.

To officially cancel the power or effect of something (such as a law, order, or privilege).

Since *vocare* means “to call” in Latin, to revoke is to “callback.” Your driver's license could be revoked after about three convictions for driving under the influence of alcohol; some people's licenses are even revoked for life. You could get your passport revoked if a judge thought you had violated the terms of your bail and suspected you might skip the country. And if you're out of prison on probation and violate the terms of probation, it will probably be revoked and you'll end up back in the slammer.

To return to an earlier and usually worse or less developed condition or state.

As you might guess, *regress* is the opposite of *progress*. So if a disease regresses, that's generally a good thing, but in most other ways we prefer not to regress. If someone's mental state has been improving, we hope he or she won't start to regress; and when a nation's promising educational system begins to regress, that's a bad sign for the country's future. Economists often distinguish between a *progressive* tax and a *regressive* tax; in a progressive tax, the percentage that goes to taxes gets larger as the amount of money being taxed gets larger, while in a regressive tax the percentage gets smaller. (Rich people prefer regressive taxes.)