Nevertheless is not to be satisfied with just part (5,3)
I believe the answer is:
after all
'nevertheless' is the definition.
(after all can mean nevertheless)
'not to be satisfied with just part' is the wordplay.
I cannot quite see how this works, but
'part' could be 'aft' (I have seen 'Rear part ' mean 'aft' so perhaps 'part' could also mean 'aft') and 'aft' is found in the answer.
This explanation may well be incorrect...
'is' acts as a link.
Can you help me to learn more?
(Other definitions for after all that I've seen before include "Nevertheless, when everything has been considered" , "anyway" , "most importantly" , "when push comes to shove" , "Where most dictionary entries are" .)