Frank talking away, gave address west of Northern Cape (13)
I believe the answer is:
outspokenness
'address west of northern cape' is the definition.
The definition and answer can be both human attributes as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'frank talking away' is the wordplay.
'frank' becomes 'outspoken' (synonyms).
'talking away' becomes 'ness' (I can't justify this - if you can you should believe this answer much more).
'outspoken'+'ness'='OUTSPOKENNESS'
'gave' is the link.
Can you help me to learn more?
(Other definitions for outspokenness that I've seen before include "Lack of verbal restraint" , "Candour" .)