Question: What is the meaning of the name of the oldest surviving Buddhist school?

full_context: Document 1: Buddhism: According to a demographic analysis reported by Peter Harvey (2013): Mahayana has 360 million adherents; Theravada has 150 million adherents; and Vajrayana has 18,2 million adherents. Seven million additional Buddhists are found outside of Asia.
Document 2: Buddhism: Only the Theravada school does not include the Mahayana scriptures in its canon. As the modern Theravada school is descended from a branch of Buddhism that diverged and established itself in Sri Lanka prior to the emergence of the Mahayana texts, debate exists as to whether the Theravada were historically included in the hinayana designation; in the modern era, this label is seen as derogatory, and is generally avoided.
Document 3: Buddhism: The Pāli Tipitaka, which means "three baskets", refers to the Vinaya Pitaka, the Sutta Pitaka, and the Abhidhamma Pitaka. The Vinaya Pitaka contains disciplinary rules for the Buddhist monks and nuns, as well as explanations of why and how these rules were instituted, supporting material, and doctrinal clarification. The Sutta Pitaka contains discourses ascribed to Gautama Buddha. The Abhidhamma Pitaka contains material often described as systematic expositions of the Gautama Buddha's teachings.
Document 4: Buddhism: The Theravada school spread south from India in the 3rd century BCE, to Sri Lanka and Thailand and Burma and later also Indonesia. The Dharmagupta school spread (also in 3rd century BCE) north to Kashmir, Gandhara and Bactria (Afghanistan).
Document 5: Buddhism: According to the scriptures, soon after the death of the Buddha, the first Buddhist council was held; a monk named Mahākāśyapa (Pāli: Mahākassapa) presided. The goal of the council was to record the Buddha's teachings. Upāli recited the vinaya. Ānanda, the Buddha's personal attendant, was called upon to recite the dhamma. These became the basis of the Tripitaka. However, this record was initially transmitted orally in form of chanting, and was committed to text in the last century BCE. Both the sūtras and the vinaya of every Buddhist school contain a wide variety of elements including discourses on the Dharma, commentaries on other teachings, cosmological and cosmogonical texts, stories of the Gautama Buddha's previous lives, and various other subjects.
Document 6: Buddhism: During the period of Late Mahayana Buddhism, four major types of thought developed: Madhyamaka, Yogacara, Tathagatagarbha, and Buddhist Logic as the last and most recent. In India, the two main philosophical schools of the Mahayana were the Madhyamaka and the later Yogacara. According to Dan Lusthaus, Madhyamaka and Yogacara have a great deal in common, and the commonality stems from early Buddhism. There were no great Indian teachers associated with tathagatagarbha thought.
Document 7: Buddhism by country: China is the country with the largest population of Buddhists, approximately 244 million or 18.2% of its total population. They are mostly followers of Chinese schools of Mahayana, making this the largest body of Buddhist traditions. Mahayana, also practiced in broader East Asia, is followed by over half of world Buddhists.
Document 8: Buddhism: In addition, Mahayana Buddhists believe there are innumerable other Buddhas in other universes. A Theravada commentary says that Buddhas arise one at a time in this world element, and not at all in others. The understandings of this matter reflect widely differing interpretations of basic terms, such as "world realm", between the various schools of Buddhism.
Document 9: Buddhism: Approximately six hundred Mahayana sutras have survived in Sanskrit or in Chinese or Tibetan translations. In addition, East Asian Buddhism recognizes some sutras regarded by scholars as of Chinese rather than Indian origin.
Document 10: Buddhism: Two major extant branches of Buddhism are generally recognized by scholars: Theravada ("The School of the Elders") and Mahayana ("The Great Vehicle"). Vajrayana, a body of teachings attributed to Indian siddhas, may be viewed as a third branch or merely a part of Mahayana. Theravada has a widespread following in Sri Lanka and Southeast Asia. Mahayana which includes the traditions of Pure Land, Zen, Nichiren Buddhism, Shingon, and Tiantai (Tendai) is found throughout East Asia. Tibetan Buddhism, which preserves the Vajrayana teachings of eighth century India, is practiced in regions surrounding the Himalayas, Mongolia and Kalmykia. Buddhists number between an estimated 488 million[web 1] and 535 million, making it one of the world's major religions.
Document 11: Buddhism: Theravada ("Doctrine of the Elders", or "Ancient Doctrine") is the oldest surviving Buddhist school. It is relatively conservative, and generally closest to early Buddhism. The name Theravāda comes from the ancestral Sthāvirīya, one of the early Buddhist schools, from which the Theravadins claim descent. After unsuccessfully trying to modify the Vinaya, a small group of "elderly members", i.e. sthaviras, broke away from the majority Mahāsāṃghika during the Second Buddhist council, giving rise to the Sthavira sect. Sinhalese Buddhist reformers in the late nineteenth and early twentieth centuries portrayed the Pali Canon as the original version of scripture. They also emphasized Theravada being rational and scientific.
Document 12: Buddhism: China is the country with the largest population of Buddhists, approximately 244 million or 18.2% of its total population.[web 1] They are mostly followers of Chinese schools of Mahayana, making this the largest body of Buddhist traditions. Mahayana, also practiced in broader East Asia, is followed by over half of world Buddhists.[web 1]
Document 13: Buddhism: According to most scholars, at some period after the Second Council the Sangha began to break into separate factions.[note 37] The various accounts differ as to when the actual schisms occurred. According to the Dipavamsa of the Pāli tradition, they started immediately after the Second Council, the Puggalavada tradition places it in 137 AN, the Sarvastivada tradition of Vasumitra says it was in the time of Ashoka and the Mahasanghika tradition places it much later, nearly 100 BCE.
Document 14: Buddhism: Over the years, various attempts have been made to synthesize a single Buddhist text that can encompass all of the major principles of Buddhism. In the Theravada tradition, condensed 'study texts' were created that combined popular or influential scriptures into single volumes that could be studied by novice monks. Later in Sri Lanka, the Dhammapada was championed as a unifying scripture.
Document 15: Buddhism: Formal membership varies between communities, but basic lay adherence is often defined in terms of a traditional formula in which the practitioner takes refuge in The Three Jewels: the Buddha, the Dharma (the teachings of the Buddha), and the Sangha (the Buddhist community). At the present time, the teachings of all three branches of Buddhism have spread throughout the world, and Buddhist texts are increasingly translated into local languages. While in the West Buddhism is often seen as exotic and progressive, in the East it is regarded as familiar and traditional. Buddhists in Asia are frequently well organized and well funded. In countries such as Cambodia and Bhutan, it is recognized as the state religion and receives government support. Modern influences increasingly lead to new forms of Buddhism that significantly depart from traditional beliefs and practices.
ground_truth: The School of the Elders
sub_queries: What is the oldest surviving Buddhist school? Answer: Theravada
Theravada means what? Answer: The School of the Elders