Stone married English girl, then engineered hit (8)
I believe the answer is:
megalith
'stone' is the definition.
(I have seen 'Large stone ' mean 'megalith' so perhaps 'stone' could also mean 'megalith')
'married english girl then engineered hit' is the wordplay.
'married' becomes 'm'.
'english' becomes 'e' (abbreviation).
'girl' becomes 'gal' ('gal' can be a synonym of 'girl'**).
'then' means one lot of letters go next to another.
'engineered' is an anagram indicator (I've seen this in other clues).
'hit' is an anagram of 'ith'.
'm'+'e'+'gal'+'ith'='MEGALITH'
(Other definitions for megalith that I've seen before include "Huge ancient monument stone" , "Large stone in a prehistoric monument" , "Upright (prehistoric) stone" , "Huge stone used in prehistoric monuments" .)