Around middle of town, salesperson reflected authority (5)
I believe the answer is:
power
'authority' is the definition.
(I've seen this before)
'around middle of town salesperson reflected' is the wordplay.
'around' means one lot of letters goes inside another.
'middle of' says to take the centre.
'salesperson' becomes 'rep' (sales rep).
'reflected' is a reversal indicator (letters reflected back).
The centre of 'town' is 'ow'.
'rep' in reverse letter order is 'per'.
'ow' placed within 'per' is 'POWER'.
(Other definitions for power that I've seen before include "Physical strength" , "index" , "product" , "Exponent" , "Strength or authority" .)