A vulnerable point.

When the hero Achilles was an infant, his sea-nymph mother dipped him into the river Styx to make him immortal. But since she held him by one heel, this spot did not touch the water and so remained mortal and vulnerable, and it was here that Achilles was eventually mortally wounded. Today, the tendon that stretches up the calf from the heel is called the *Achilles tendon*. But the term *Achilles ' heel* isn't used in medicine; instead, it's only used with the general meaning “weak point”—for instance, to refer to a section of a country's borders that aren't militarily protected, or to a *Jeopardy* contestant's ignorance in the Sports category.

A region or setting of rural pleasure and peacefulness.

Arcadia, a beautiful rural area in Greece, became the favorite setting for poems about ideal innocence unaffected by the passions of the larger world, beginning with the works of the Roman poet Virgil. There, shepherds play their pipes and sigh with longing for flirtatious nymphs; shepherdesses sing to their flocks; and goat-footed nature gods play in the fields and woods. Today, city dwellers who hope to retire to a country house often indulge in *arcadian* fantasies about what rural life will be like.

A person who predicts misfortune or disaster.

Cassandra, the daughter of King Priam of Troy, was one of those beautiful young maidens with whom Apollo fell in love. He gave her the gift of prophecy in return for the promise of her sexual favors, but at the last minute she refused him. Though he could not take back his gift, he angrily pronounced that no one would ever believe her predictions; so when she prophesied the fall of her city to the Greeks and the death of its heroes, she was laughed at by the Trojans. A modern-day Cassandra goes around predicting gloom and doom—and may turn out to be right some of the time.

Huge or massive.

The Cyclopes of Greek mythology were huge, crude giants, each with a single eye in the middle of his forehead. Odysseus and his men had a terrible encounter with a Cyclops, and escaped utter disaster only by stabbing a burning stick into the monster's eye. The great stone walls at such ancient sites as Troy and Mycenae are called cyclopean because the stones are so massive and the construction (which uses no cement) is so expert that it was assumed that only a superhuman race such as the Cyclopes could have achieved such a feat.

Extremely severe or cruel.

*Draconian* comes from the name of Draco, a leader of Athens in the 7th century B.C. who in 621 B.C. produced its first legal code. The punishments he prescribed were extraordinarily harsh; almost anyone who couldn't pay his debts became a slave, and even minor crimes were punishable by death. So severe were these penalties that it was said that the code was written in blood. In the next century, the wise leader Solon would revise all of Draco's code, retaining the death penalty only for the crime of murder.

A loyal follower, especially one who executes orders unquestioningly.

In the Trojan War, the troops of the great hero Achilles were called Myrmidons. As bloodthirsty as wolves, they were the fiercest fighters in all Greece. They were said to have come from the island of Aegina, where, after the island's entire population had been killed by a plague, it was said to have been repopulated by Zeus, by turning all the ants in a great anthill into men. Because of their insect origin, the Myrmidons were blindly loyal to Achilles, so loyal that they would die without resisting if ordered to. The Trojans would not be the last fighting force to believe that a terrifying opposing army was made up of men who were not quite human.

A powerful, frightening opponent or rival who is usually victorious.

The Greek goddess Nemesis doled out rewards for noble acts and vengeance for evil ones, but it's only her vengeance that anyone remembers. According to the Greeks, Nemesis did not always punish an offender right away, but might wait as much as five generations to avenge a crime. Regardless, her cause was always just and her eventual victory was sure. But today a nemesis doesn't always dispense justice; a powerful drug lord may be the nemesis of a Mexican police chief, for instance, just as Ernst Stavro Blofeld was James Bond's nemesis in three of Ian Fleming's novels.

Someone or something that works from within to weaken or defeat.

After besieging the walls of Troy for ten years, the Greeks built a huge, hollow wooden horse, secretly filled it with armed warriors, and presented it to the Trojans as a gift for the goddess Athena, and the Trojans took the horse inside the city's walls. That night, the armed Greeks swarmed out and captured and burned the city. A Trojan horse is thus anything that looks innocent but, once accepted, has power to harm or destroy—for example, a computer program that seems helpful but ends up corrupting or demolishing the computer's software. ```