Atmakaya, Ātmakāya, Atman-kaya: 2 definitions
Introduction:
Atmakaya means something in Buddhism, Pali, Hinduism, Sanskrit. If you want to know the exact meaning, history, etymology or English translation of this term then check out the descriptions on this page. Add your comment or reference to a book if you want to contribute to this summary article.
In Hinduism
Yoga (school of philosophy)
Source: ORA: Amanaska (king of all yogas): A Critical Edition and Annotated Translation by Jason BirchĀtmakāya (आत्मकाय) refers to “one’s own body”, according to the Amanaska Yoga treatise dealing with meditation, absorption, yogic powers and liberation.—Accordingly, as Īśvara says to Vāmadeva: “[...] [Now], I shall define the nature of that highest, mind-free absorption which arises for those devoted to constant practice. [...] [The yogin] who has remained in absorption continually for twenty-four years, [gains] the Siddhi of the Śakti element. Indeed, he becomes absorbed in the Śakti element. [The Yogin] will see the entire universe like a pearl held in [his] hand and truly understand its essential nature [to be] in his own body (ātmakāya-svarūpa). [...]”.

Yoga is originally considered a branch of Hindu philosophy (astika), but both ancient and modern Yoga combine the physical, mental and spiritual. Yoga teaches various physical techniques also known as āsanas (postures), used for various purposes (eg., meditation, contemplation, relaxation).
In Buddhism
Mahayana (major branch of Buddhism)
Source: Wisdom Library: Maha Prajnaparamita SastraĀtmakāya (आत्मकाय) refers to “one’s own body”, according to Mahāprajñāpāramitāśāstra (chapter 31).—Accordingly, “Without knowing if the ātman exists or does not exist, you are asking why one does not produce the idea of the ātman in regard to another. [The distinctions] between one’s own body (ātmakāya) and another’s body (parakāya) exist as a function of the Ātman. But the Ātman is non-existent. [The characteristics attributed to it]: having form (rūpin) or formless (arūpin), permanent (nitya) or impermanent (anitya), finite (antavat) or infinite (ananta), moveable (gantṛ) or motionless (agantṛ), cognizant (jñātṛ) or ignorant (ajñātṛ), active (kāraka) or inactive (akāraka), autonomous (svatantra) or non-autonomous (asvatantra): all these characteristics of the ātman do not exist, as we have said above in the chapter on the Ātman. [...]”.

Mahayana (महायान, mahāyāna) is a major branch of Buddhism focusing on the path of a Bodhisattva (spiritual aspirants/ enlightened beings). Extant literature is vast and primarely composed in the Sanskrit language. There are many sūtras of which some of the earliest are the various Prajñāpāramitā sūtras.
See also (Relevant definitions)
Full-text: Anuyoga, Svatantra, Antavat, Parakaya, Rupi, Akaraka, Asvatantra, Ajnatri, Gantri, Agantri, Ananta, Jnata, Dharmasmrityupasthana, Arupi, Karaka.
Relevant text
Search found 2 books and stories containing Atmakaya, Ātma-kāya, Atma-kaya, Ātmakāya, Ātman-kāya, Atman-kaya; (plurals include: Atmakayas, kāyas, kayas, Ātmakāyas). You can also click to the full overview containing English textual excerpts. Below are direct links for the most relevant articles:
Maha Prajnaparamita Sastra (by Gelongma Karma Migme Chödrön)
Mahāyāna auxiliaries (A): The four foundations of mindfulness < [Part 3 - The auxiliaries according to the Mahāyāna]
E.1: The Four Foundations of Mindfulness (smṛtyupasthāna) < [Abhidharma auxiliaries (E): Detailed study of the auxiliaries]