Actually it depends upon its usage but basically "na naman" means again.
• Umuulan na naman. (It is raining again.)
• Hindi ko na naman siya nakita. (I was not able to see her again.)
• Masaya na naman siya. (She was happy again.)
If this is not clear to you, feel free to drop me a message and I'll be more than willing to explain it further. :)
February 23, 2012
in addition, a tagolog synonyms for "na naman" would be "uli","ulit" or "muli". seldom you will read 'na naman' in a formal writings.
'hindi ko na naman siya nakita.' = 'hindi ko ulit siya nakita.'