Ascetic: A person who renounces all earthly pleasures as part of their search for spiritual truth.
Caste system: A system of ranking people into very specific social groups, which prevailed in India from ancient times to the modern day.
Charioteer: Someone who drives a chariot, a horse-drawn wagon.
Citadel: A fortress.
Civil servant: Someone who works for the government.
Commentary: A written work that helps to explain another work.
Craftsman: A skilled worker who produces items according to his specialty.
Cremation: The burning, as opposed to the burying, of a dead body.
Deforestation: Cutting down trees and other plant life, which often has disastrous environmental consequences.
Domesticate: To tame a wild animal.
Drainage system: The use of pipes and sewers to transport waste water from a high-population area to a place where it can be disposed of safely.
Economy: The whole system of production, distribution, and consumption of goods and services in a country.
Enlightenment: In Eastern religions, a state of being at one with God, the universe, or some other form of higher truth.
Epic: A long poem that recounts the adventures of a legendary hero.
Fasting: Deliberately going without food, often but not always for religious reasons.
Godhead: The divine nature or essence of God.
Granaries: Warehouses for storing grain.
Grid: A network of evenly spaced lines that intersect one another at right angles, as horizontal and vertical lines do.
Immunization: Taking measures to protect people from getting a specific illness, often by injecting them with a small dose of the virus that causes the illness.
Indo-European languages: The languages of Europe, India, Iran, and surrounding areas, all of which share common roots.
Industrial Revolution: A period of rapid development, beginning in about a. d. 1750, which transformed the economies of the West from agriculture-based to manufacturing-based systems.
Irrigation: A method of keeping crops watered, often by redirecting water supplies.
Islam: A faith that arose in Arabia in the a. d. 600s, led by the prophet Muhammad (A. D. 570?-632).
Linguist: A scholar who studies languages.
Literary: Referring to or involving literature.
Mantra: A chant used by participants in Eastern meditation, thought to aid the worshiper in concentrating on the Godhead.
Mass-production: A manufacturing system in which goods are produced in large quantities, rather than one at a time.
Meditation: In Eastern religion, the focusing of one's thoughts on the Godhead, which usually takes place in an atmosphere of stillness and quiet.
Metropolis: A very large, important city.
Middle Ages: The period from the fall of the Roman Empire to the beginning of the Renaissance, roughly a. d. 500 to 1500.
Middle class: A group in between the rich and the poor, or between the rich and the working class.
Migration: Movement by a large group of people from one place to another.
Missionaries: People who travel to other lands with the aim of converting others to their religion.
Pantheon: All the recognized gods in a religion.
Pyre: A bonfire on which a body is cremated.
Racist: A person who believes that race is the primary factor that determines peoples' abilities and that one race is superior to others.
Raja: An Indian noble or prince of lesser rank than a king or an emperor.
Reincarnation: The idea that people are reborn on earth, and live and die, again and again.
Renaissance: A period of renewed interest in learning and the arts that began in Europe in the 1300s and continued to the 1700s.
Ritual: A type of religious ceremony that is governed by very specific rules.
Seal: An emblem or a symbol that takes the place of a name or signature, which is often pressed into wax or hot clay to make a permanent mark.
Shrine: A holy place for believers of a religion.
Soma: An intoxicating drink used in Vedic and Zoroastrian religious rituals.
Stupa: A dome-shaped Buddhist temple.
Sultan: A type of king in the Muslim world.
Trade: The exchange of goods for units of value (money, gold, or other goods) between two individuals or two countries.
Trinity: A group of three gods, usually the highest in a religion.
Urban planning/city planning: Careful design of cities to handle problems such as overcrowding, traffic, and waste disposal.
Vegetarian: Someone who does not eat meat or—in some cases—products such as eggs and cheese that come from animals.
Ple who lived south of the Sahara Desert in Africa, however, there is no clear evidence that they came from that part of the world. What is clear is that the Indo-Europeans looked down on the peoples they conquered. Yet the Indus Valley civilization was one of the most advanced in all of human history.