Polynesian tattoo needing addition without filling (6)
I believe the answer is:
tongan
'polynesian' is the definition.
(Tongan is an example)
'tattoo needing addition without filling' is the wordplay.
'tattoo' becomes 'tong' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'needing' is a charade indicator (letters next to each other).
'without filling' says to hollow out the word (remove centre letters).
'addition' with its middle taken out is 'an'.
'tong'+'an'='TONGAN'
Can you help me to learn more?
(Other definitions for tongan that I've seen before include "Language" , "One from the Friendly Islands, as was" , "Friendly Islander" .)