(1) Able to be dissolved in a liquid, especially water. (2) Able to be solved or explained.

*Soluble* looks like a word that should be confined to chemistry labs, though it's often used by nonchemists as well to describe substances that can be dissolved in liquids. On the other hand, the sense of *soluble* meaning “solvable” is also quite common. In this sense, *soluble,* like its opposite, *insoluble,* is usually paired with *problem.* If only all life's problems were soluble by stirring them in a container filled with water.

The act of forgiving someone for their sins.

Since the Latin *absolutus* meant “set free,” it's easy to see how *absolution* came to mean “set free from sin.” (And also easy to see why *absolute* means basically “pure”—that is, originally, “free of sin.”) The verb for *absolution* is *absolve*. Just as a priest absolves believers of their sins, you may absolve your brother of blame for a household disaster, or you yourself may in time be absolved for that scrape on the car backing out of a parking space.

The act or process of breaking down or apart into basic components, as through disruption or decay.

*Dissolution* is the noun form of *dissolve*, but it's a much less common word. Still, we refer to the fact that the dissolution of American marriages became far more common in the later 20th century. Or that when India won its independence in 1948, the dissolution of the once-global British empire was all but complete. Or that factors such as crime and drugs might be contributing to the dissolution of contemporary society's moral fabric. A *dissolute* person is someone in whom all restraint has dissolved, and who now indulges in behavior that shocks decent people.

Marked by firm determination.

*Resolute* comes from the same Latin verb as *resolved*, and the two words are often synonyms. So how did it get this meaning from the Latin? Essentially, when you resolve a question or problem, you come to a conclusion, and once you've reached a conclusion you can proceed to act. So in your New Year's *resolutions*, you resolve—or make up your mind—to do something. Unfortunately, New Year's resolutions aren't a good illustration of the meaning of *resolute*, since only about one in ten actually seems to succeed.

(1) Relating to water; operated, moved, or brought about by means of water. (2) Operated by the resistance or pressure of liquid forced through a small opening or tube.

By means of a hydraulic lift, the driver can lift the bed of a dump truck with the touch of a button. He might also repair the hydraulic steering, the hydraulic brake, or the hydraulic clutch—all of which, like the lift that holds everything up, take advantage of the way liquids act under pressure. Somewhat like a pulley or a lever, a hydraulic system magnifies the effect of moderate pressure exerted over a longer distance into powerful energy for a shorter distance.

(1) To remove water from. (2) To deprive of energy and zest.

Dehydrating food is a good way to preserve it; raisins, which are dehydrated grapes, are a good example. *Dehydration* through industrial processes makes it possible to keep food even longer and store it in a smaller space. Freeze- drying produces food that only needs *rehydration*—that is, the addition of water—to restore its original consistency. Runners, cyclists, and hikers fearful of dehydration seem to be constantly *hydrating* themselves nowadays, sometimes even using a shoulder pack with a tube going straight into the mouth. *Dehydrate* can also be used for making something “dry” or “lifeless” ; thus, a dull teacher can dehydrate American history, and an unimaginative staging can dehydrate a great Shakespeare play.

Having to do with the production of electricity by waterpower.

The prime component of most hydroelectric systems is a dam. A high dam funnels water downward at high pressure to spin turbines, which in turn drive generators to produce high-voltage electricity. Mountainous countries with rushing rivers can produce the most *hydroelectricity.* Though hydroelectricity comes from a clean and completely renewable energy source, dams disrupt natural systems in a way that disturbs environmentalists.

The growing of plants in nutrient solutions, with or without supporting substances such as sand or gravel.

Hydroponics, also known as *aquaculture* or *tank farming*, began as a way of studying scientifically the mechanisms of plant nutrition. Hydroponically grown plants may have no solid material under them at all; instead, their roots often simply hang in water with a rich mix of nutrients dissolved in it. The principal advantage to hydroponics is the savings from reduced labor costs, since it's generally carried on in enclosed areas and the irrigation and fertilizing are done mechanically. Peppers, cucumbers, and various other vegetables are produced *hydroponically* in huge quantities.