Engineers curse about saviour (7)
I believe the answer is:
rescuer
'saviour' is the definition.
(I know that saviour can be written as rescuer)
'engineers curse about' is the wordplay.
'engineers' becomes 're' (Royal Engineers).
'about' indicates an anagram.
'curse' is an anagram of 'scuer'.
're'+'scuer'='RESCUER'
(Other definitions for rescuer that I've seen before include "One who delivers" , "One who saves another from peril" , "One who saves from a dangerous situation" , "one retrieves" , "Deliverer (from danger)" .)