Papa not polite and nice, not one for discretion (8)
I believe the answer is:
prudence
'discretion' is the definition.
(synonyms)
'papa not polite and nice not one' is the wordplay.
'papa' becomes 'p' (phonetic alphabet: alpha, bravo, charlie etc.).
'not polite' becomes 'rude' ('rude' is the opposite to 'polite').
'and' says to put letters next to each other.
'not' indicates named letters should be taken away.
'one' becomes 'i' (Roman numeral).
'nice' with 'i' taken away is 'nce'.
'p'+'rude'+'nce'='PRUDENCE'
'for' is the link.
(Other definitions for prudence that I've seen before include "Care and thought for the future" , "Quality of being cautious and sensible, and a girl's name" , "Shrewdness in planning ahead" , "Wise caution" , "A woman < 's > circumspection" .)