See you within days accumulate capital (8)
I believe the answer is:
damascus
'capital' is the definition.
(Damascus is an example)
'see you within days accumulate' is the wordplay.
'see' becomes 'c' (the word for the letter, according to Chambers).
'you' becomes 'u' (I've seen this in other clues**).
'within' indicates putting letters inside.
'days' becomes 'd'.
'accumulate' becomes 'amass' ('amass' can be a synonym of 'accumulate').
'c'+'u'='cu'
'd'+'amass'='damass'
'cu' inserted inside 'damass' is 'DAMASCUS'.
(Other definitions for damascus that I've seen before include "Syrian capital" , "Pauline conversion on the road to here" , "St Paul was converted on the road to this Syrian city" , "ancient city" , "capital city" .)