JK> Can anyone tell me the subtleties of difference in
JK> meaning between all the words "jaati sa~njaati okkanti
JK> nibbatti abhinibbatti"? To me they all seem to be
JK> synonymous with a general sense of "birth, becoming,
JK> rebirth".
As far as I can say,
jaati - birth
sa~njaati - production
okkanti - coming to be
nibbatti - rebirth
abhinibbatti - becoming
such list of shades of meanings is typical for definitions.
You can look up Rhys Davids and Monier-Williams dictionaries.