query: What is the origin of the word Tehran?
passage: Tehran
Tehran (/tɛəˈræn, -ˈrɑːn, ˌteɪə-/; Persian: تهران‎ Tehrân [tehˈɾɒːn](listen)) is the capital of Iran and Tehran Province. With a population of around 8.4 million in the city and 15 million in the larger metropolitan area of Greater Tehran, Tehran is the most populous city in Iran and Western Asia,[6] and has the second-largest metropolitan area in the Middle East. It is ranked 29th in the world by the population of its metropolitan area.[7]
passage: Tehran
Tehran is the economic center of Iran.[52] About 30% of Iran's public-sector workforce and 45% of its large industrial firms are located in the city, and almost half of these workers are employed by the government.[53] Most of the remainder of workers are factory workers, shopkeepers, laborers, and transport workers.