1. The title ācārya is primarily applied to a Hindu teacher who invests the student with the sacrificial thread (vajñopavīta) and instructs him in the vedas and the religious law (dharma). By extension it is applied to a spiritual preceptor, or to anyone learned in the Hindu tradition. This title is frequently affixed directly to the proper name, e.g. Śaṅkarācārya.
2. In particular, a group of Tamil Vaiṣṇava teachers regarding the Āḻvārs as incarnations of Viṣṇu's instruments/weapons. The first was Nāthamuni (9th cent. CE).
3. In Buddhism Pāli, ācāriya), teacher of the dhamma, in contrast to upāydhyāya, who taught discipline and the rules.
4. Among Jains, the ācārya holds a vital place in teaching and in the transmission of lineage (for an example, see BHIKṢU, ĀCĀRYA).
"Ācārya." The Concise Oxford Dictionary of World Religions. . Encyclopedia.com. (November 17, 2018). https://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/acarya
"Ācārya." The Concise Oxford Dictionary of World Religions. . Retrieved November 17, 2018 from Encyclopedia.com: https://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/acarya
Modern Language Association
The Chicago Manual of Style
American Psychological Association
Acarya: see Bhaskara.
"Acarya." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. (November 17, 2018). https://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/acarya
"Acarya." The Columbia Encyclopedia, 6th ed.. . Retrieved November 17, 2018 from Encyclopedia.com: https://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/acarya