Round the fringes of Belfast, employment is slow on the uptake (6)
I believe the answer is:
obtuse
'slow on the uptake' is the definition.
(I've seen this in another clue)
'round the fringes of belfast employment' is the wordplay.
'round' becomes 'o' (o is a circular letter).
'the fringes of' means to remove the middle letters.
'employment' becomes 'use' (how something is used).
'belfast' with its middle removed is 'bt'.
'o'+'bt'+'use'='OBTUSE'
'is' acts as a link.
(Other definitions for obtuse that I've seen before include "Dopey" , "Annoyingly insensitive" , "Blunt - stupid - insensitive" , "not acute?" , "Dim-witted" .)