Got better engineers insured (9)
I believe the answer is:
recovered
'got better' is the definition.
('recover' can be a synonym of 'get better')
'engineers insured' is the wordplay.
'engineers' becomes 're' (abbreviation for Royal Engineers).
'insured' becomes 'covered' ('cover' can be a synonym of 'insure').
're'+'covered'='RECOVERED'
(Other definitions for recovered that I've seen before include "Found after being lost" , "Got better" , "Took back" , "Returned to health; got back" , "Well now!" .)