Forbidding use at work with engineers (7)
I believe the answer is:
austere
'forbidding' is the definition.
('austere' can be a synonym of 'forbidding')
'use at work with engineers' is the wordplay.
'work with' indicates an anagram.
'engineers' becomes 're' (Royal Engineers**).
'use'+'at'='useat'
'useat' is an anagram of 'auste'.
'auste'+'re'='AUSTERE'
(Other definitions for austere that I've seen before include "Stern or very plain" , "not of luxury type" , "Strict in appearance" , "Severe, lacking comforts" , "Serious" .)