Engineered, and hence improved (8)
I believe the answer is:
enhanced
'improved' is the definition.
(enhancing is a kind of improving)
'engineered and hence' is the wordplay.
'engineered' is an anagram indicator (I've seen this in other clues).
'and'+'hence'='andhence'
'andhence' anagrammed gives 'ENHANCED'.
(Other definitions for enhanced that I've seen before include "Increased in value or quality" , "And hence? (anag)" , "Improved (upon)" , "Increased number" , "Heightened" .)