Flies perhaps hurry quicker round gent's middle (3,8)
I believe the answer is:
zip fastener
'flies perhaps' is the definition.
(flies can mean a zip fastener)
'hurry quicker round gent's middle' is the wordplay.
'hurry' becomes 'zip' (synonyms).
'quicker' becomes 'faster' ('fast' can be similar in meaning to 'quick').
'round' is an insertion indicator.
'middle' says to take the centre.
The middle letters of 'gent' are 'en'.
'faster' placed around 'en' is 'fastener'.
'zip'+'fastener'='ZIP-FASTENER'
(Other definitions for zip fastener that I've seen before include "Substitute for buttons" , "Locking device with two toothed edges and a sliding tab" , "Flies" , "It replaces buttons" .)