Unbroken company detachment retreating in common sense (10)
I believe the answer is:
continuous
'unbroken' is the definition.
(associated in meaning)
'company detachment retreating in common sense' is the wordplay.
'company' becomes 'co' (abbreviation).
'detachment' becomes 'unit' (I've seen this before).
'retreating' is a reversal indicator.
'in' is an insertion indicator.
'common sense' becomes 'nous' (nous is a kind of common sense).
'unit' backwards is 'tinu'.
'tinu' inserted into 'nous' is 'ntinuous'.
'co'+'ntinuous'='CONTINUOUS'
(Other definitions for continuous that I've seen before include "without stopping" , "Uninterrupted" , "Without interruption" .)