What is the Buddhist definition of "Atta"? There are many discussions about Anatta or Not-Self in Buddhist communities, but the definition of Atta or self is uncommon and not clear. People often misunderstand or superficially translate it, using the definition of the English word "self", which means "internal of individual being", or "colloquial personal point of view of individual being", just differentiation of other individual being.

My question here is, other than just this colloquial definition of Self or Atta, is there any more insightful definition of Atta in human being, for example does it imply some "essence" (closer to Hindu or Brahmanist definition of 'Attaman'). 

If 'Atta' is physical body?


What happen if a person died and leave physical body behind (in cemetery)


If 'Atta' is mind (Citta)?


Buddhism definition of mind (Citta) bodies are transitional and conditional factors (depending on or composed with contact, feeling, memorizing, judging etc). So it seems in a sense to process by just following Citta Laws (Niyamas) than being essence, core or Atta. (Process than essence). 


If rebirth is a footprint of 'Atta'? 


Rebirth seems continuity and information/karma/effects carried over but statistically we do not have enough proof (there should be many Einsteins if we have studied mathematics or physics many lives but instead we have only a handful of geniuses on particular study, information/karma/effects carried over is somehow lost or continuity is weak and/or broken). 


If wholesome acts is 'Atta'?


Vipasana wholesome acts are as well not 'Atta' because I heard that during meditation or Vipasana "Only Sankhara dhammas are observing Sankhara dhammas (Sati, Samadhi, Panna are also encouraged by Cetana, initiated by Sanna and many more supporting factors). The observings are effects of efforts to happen at the same time the observants are not 'Atta'. 


So in conclusion, when we are saying self or 'Atta', which particular entity is defined to be called self or 'Atta'. If not a single entity, which collective entities are defined to be called self or 'Atta' and why can it be called self or 'Atta'?
From the viewpoint of Buddhist practise, as explained in SN 22.81, 'atta' ('self') refers to an ignorance created 'thought formation' (sankhara) that ignorantly assumes self-identity &amp; ownership in relation to any of the five aggregates. 

This ignorant assumption of self-identity &amp; ownership is central in the generation of suffering, as explained in SN 22.1 and as explained in Dependent Origination (SN 12.2).

Therefore, in Buddhism, the primary importance of 'atta' is it is a central cause of suffering that is ever-present in the mind of the unenlightened person ('uninstructed worldling'). 


  Here, bhikkhus, the uninstructed worldling ... assumes form as self (attato). That assumption, bhikkhus, is a formation (saṅkhāro). That
  formation — what is its source, what is its origin, from what is it born (jatiko)
  and produced? When the uninstructed worldling is contacted by a
  feeling born of ignorance-contact, craving arises: thence that
  formation (of 'self') is born. SN 22.81





  There is the case where an uninstructed, run-of-the-mill person — assumes form (the body) to be the self or the self as possessing
  form or form as in the self or the self as in form. He is seized
  with the idea that 'I am form' or 'Form is mine.' As he is seized with
  these ideas, his form changes &amp; alters, and he falls into sorrow,
  lamentation, pain, distress &amp; despair over its change &amp; alteration.
  
  There is the case where a well-instructed disciple of the noble ones — who has regard for noble ones, is well-versed &amp;
  disciplined in their Dhamma; who has regard for men of integrity, is
  well-versed &amp; disciplined in their Dhamma — does not assume form to be
  the self or the self as possessing form or form as in the self or
  the self as in form. He is not seized with the idea that 'I am form'
  or 'Form is mine.' As he is not seized with these ideas, his form
  changes &amp; alters, but he does not fall into sorrow, lamentation, pain,
  distress or despair over its change &amp; alteration.
  
  SN 22.1





  And what, bhikkhus, is attachment? There are these four kinds of attachment: attachment of sensual pleasures, attachment of views,
  attachment of rules and vows, attachment of words of
  'self' (attavā­du­pādā­naṃ). This is called attachment.
  
  And what, bhikkhus, is birth? The birth of the various beings (sattānaṃ) into the various orders of beings (sattanikāye)...
  
  SN 12.2


Note: 'Satta' is a synonym for 'atta', in 'satta' is also a view about 'self'. Refer to SN 5.10 &amp; SN 23.2. 




  Therefore, bhikkhus, any kind of form whatsoever ... Any kind of feeling whatsoever … Any kind of perception whatsoever … Any kind of
  volitional formations whatsoever … Any kind of consciousness
  whatsoever, whether past, future, or present, internal or external,
  gross or subtle, inferior or superior, far or near, all consciousness
  should be seen as it really is with correct wisdom thus: ‘This is not
  mine (mama), this I am (asmi) not, this is not my self (atta).’ SN
  22.59
  
  
  
  It is said that the world is empty, the world is empty, lord. In what respect is it said that the world is empty? Insofar as it is
  empty of a self (attena) or of anything pertaining to a self
  (attaniyena): Thus it is said, Ananda, that the world is empty Suñña
  Sutta