The Greek prefix *endo-* means “within, inside,” so around 1860 an early crude instrument for looking deep inside the body was named the endoscope. But modern *endoscopy* required the invention of the electric lightbulb and then fiber-optic cable, so the first modern endoscopes date only to 1967. An endoscope may be inserted through a natural passageway (for example, through the nose or down the esophagus) or through a tiny cut in the skin. A tiny camera with a light at the end of the cable sends back images onto a screen, and the surgeon uses special instruments that work through a tube alongside the cable. There are now specialized types of endoscopes for every part of the body, where they can take tissue samples, cut out small growths, or remove foreign objects.

Relating to a fiber-optic instrument that is inserted through an incision near a joint to examine the joint's interior.

In Greek, *arthron* means “joint.” *Arthritis* is a condition of swollen and painful joints, and *arthropods* are animals (including insects, arachnids, and crustaceans) that have a segmented body and jointed limbs. Arthroscopic surgery, or *arthroscopy*, has revolutionized the treatment of joint injuries. It's performed with an arthroscope, a specialized type of endoscope (see above). A tiny camera and a light are inserted through a small cut in the skin, and through another cut nearby a tiny surgical instrument, controlled through its own cable, is inserted. The surgeon then performs the operation, guided by the images sent back via the fiber-optic cable. Most patients walk out of the hospital on crutches the same day, though full recovery may take a couple of months.

Examination of the interior of the abdomen using a fiber-optic instrument inserted through a cut in the abdomen's wall.

Since *laparo-* means “wall of the abdomen,” a *laparoscope* is an endoscope designed especially to examine the abdomen. Common *laparoscopic* surgeries include removal of the gallbladder, appendix, or kidney, and removal of tumors from abdominal organs. Like the other endoscopic surgeries, laparoscopy, as compared to traditional surgery, reduces risk of bleeding, pain following the operation, patient recovery time, and length of hospital stays.

An instrument that shows visual images of changing electrical current on a screen.

In Latin *oscillare* means “to swing,” and our word *oscillation* usually means “vibration” or “variation,” especially in a changing flow of electricity. The oscilloscope basically draws a graph of an electrical signal. Since all kinds of physical phenomena can be converted into an electric voltage, oscilloscopes can be used to measure such things as sound, light, and heat. So an oscilloscope can analyze how one clarinet's sound is different from another's, or how one bulb's light differs from another's. Auto mechanics use oscilloscopes to measure engine vibrations; doctors use them to measure brain waves. Audio technicians use oscilloscopes to diagnose problems in audio equipment; TV and radio technicians use them to diagnose TV and radio problems. But oscilloscopes are most essential today to high-tech electronics experimentation.

(1) Not lasting long; short-lived. (2) Passing through a place and staying only briefly.

A transient mood is one that passes quickly. A brief stopover in a town on your way to somewhere else is a transient visit. A summer job on a farm is transient work, lasting only as long as the growing season. You may occasionally experience a transient episode of dizziness or weakness, which vanishes without a trace. As a noun, *transient* means a person who passes through a place, staying only briefly. The hoboes and tramps of earlier years were some of our most colorful transients, known for hopping freight trains, panhandling on the street, and stealing homemade pies cooling on the windowsill.

A change in form or appearance; a glorifying spiritual change.

The Gospels relate that one day Jesus took three disciples up a mountain, where they witnessed his transfiguration into divine form: his face shone like the sun, his garments became brilliantly white, and a voice from heaven proclaimed that this was the son of God. *Transfiguration* was first used in English as the name of this biblical event, and the Feast of the Transfiguration remains the name of a holy day. So the word has always kept a somewhat religious—and almost always positive—tone. A face may be transfigured by joy, and an “ugly duckling” may be slowly transfigured into a radiant beauty. And as Harry Potter fans know, transfiguration is a subject long taught at the Hogwarts School by Minerva McGonagall.

A radio or radar set that emits a radio signal after receiving such a signal.

This word was coined during World War II by simply joining pieces of the words *transmitter* and *responder*. Transponders are basic to modern aviation and communications satellites, and they're finding new uses in fields such as medicine as well. But they're now also part of everyday life. The “E-ZPass” that lets you drive right through turnpike tollbooths is a transponder, and the car you're driving may not even start unless it recognizes the signal from your personal key's transponder. In a big crowded foot race, you may carry a tiny transponder on your shoe that records when you cross both the starting line and the finish line.

(1) Exceeding or rising above usual limits; supreme. (2) Beyond comprehension; beyond ordinary experience or material existence.

The Latin verb *scandere* means “to climb,” so *transcend* has the basic meaning of climbing so high that you cross some boundary. A transcendent experience is one that takes you out of yourself and convinces you of a larger life or existence; in this sense, it means something close to “spiritual.” The American writers and thinkers known as the *Transcendentalists*, including Ralph Waldo Emerson and Henry David Thoreau, believed in the unity of all creation, the basic goodness of humankind, and the superiority of spiritual vision over mere logic. When we speak of the transcendent importance of an issue such as climate change, we may mean that everything else on earth actually depends on it.