Chitta
चित्त (chitta)
The mind-field - the whole substrate of mental activity, including memory, thought, and impression.
Chitta names the broader field of the mind, encompassing memory, thought, impression, and the accumulated residue of past experience, distinct from more specific faculties like intellect (buddhi) or ego (ahamkara), which are sometimes described as functions arising within it.
Classical yoga famously defines its own goal in terms of chitta: yoga is the stilling of the fluctuations of the mind-field. This definition is worth sitting with, because it locates the entire practice not in achieving anything external but in quieting the constant movement of an already-present field.
A still chitta is not described as an empty or blank mind. It is described as a clear one, in the way still water becomes transparent, allowing what is actually present, rather than the constant churn of thought, to become visible.