breath, soul, spirit orvital principle, as the word "Atem, Atmen" does in German.
sentient energy
There are 3 forms/stages of atma, soul:
outer soul:
bahiratma
The external soul is characterised by an aversion to the quest for truth.
inner soul:
antaratma
The internal soul is fully dedicated to the quest for truth.
supreme soul:
paramatma
One who attains self-realization is a liberated soul, supreme soul or paramatman.
A soul or atma bound by a body is called jiva, an embodied soul.