The usual meaning of 'atman' is almost exactly equivalent to western 'spirit' or 'soul', the divine spark hidden inside of us amongst all the garbage, that we have to somehow find.

In Hinduism, Brahaman is the Absolute (with an upper case 'A'), the equivalent to Godhead in much of Christianity. Atman is then the spark of Brahman that happens to make you you, and is buried inside of you, and which it is your life's purpose to find. (Do not confuse Brahman, the Hindu Absolute, with Brahma, the Hindu god of creation; nor with Brahmin, a member of the Hindu priestly caste - better yet, for minimum confusion, don't think of any of them at all!)

Your definitions from Google are an interesting westernisation of the Hindu terms - I like them, in fact.

I only used the word 'atman' since that was exactly what Maharaji used to mean, coming from his Hindu background where this was all pretty staple stuff. My understanding is that when he first started using the word 'heart' in this way, he was consciously translating it as atman.

I agree that for anyone not immersed in Hinduism (as most premies from the early years were), it is all erudite and exotic.

My main point is that Maharaji's use of the word 'heart' is to mean the divine essence or spark within each one of us, rather than (or as well as?) the emotional center of a person, which is its normal English usage.