Reverse engineering of terminus (10)
I believe the answer is:
misfortune
'reverse' is the definition.
(thesaurus)
'engineering of terminus' is the wordplay.
'engineering' indicates anagramming the letters (letters manipulated or engineered).
'of'+'terminus'='ofterminus'
'ofterminus' anagrammed gives 'MISFORTUNE'.
(Other definitions for misfortune that I've seen before include "DISASTER]" , "Adversity - bad luck" .)