Mother turning up with guy and capital (5)
I believe the answer is:
amman
'capital' is the definition.
(capital of Jordan)
'mother turning up with guy' is the wordplay.
'mother' becomes 'ma' (Ma is another word for mother or mum).
'turning up' shows that the letters should be reversed in order.
'with' is a charade indicator (letters next to each other).
'guy' becomes 'man ' (guy can informally mean a man).
'ma' backwards is 'am'.
'am'+'man'='AMMAN'
'and' acts as a link.
(Other definitions for amman that I've seen before include "City of Jordan" , "Middle East capital" , "A capital f-fellow in Jordan?" , "Jordanian capital" , "Jordan's capital" .)