Tzung Kuen,

> A further question, what is the function of 'sa-' in this
> compound 'saadhunika', since 'aadhunika' means already 'now
> living' , 'of the present moment' according to Critical Pali
> Dictionary? Both saha 'together' and saya.m 'own ' seem do
> not work here?

I am not sure, but would guess that it is either pleonastic, or else
denotes something shared or collective. As siblings are
"together-wombed", sodariya (= sa + udariya), meaning that they have
shared the same womb, so all those presently alive are
"together-moderned", that is to say, they exist together in the present
and recent time (addhunaa).

Best wishes,
Dhammanando