Blunder made by English kings (3)
I believe the answer is:
err
'blunder' is the definition.
(thesaurus)
'by english kings' is the wordplay.
'by' says to put letters next to each other.
'english' becomes 'e' (abbreviation).
'kings' becomes 'rr' (I am not sure about this - if you are sure you should believe this answer much more).
'e'+'rr' is 'ERR'.
'made' is the link.
(Other definitions for err that I've seen before include "Blunder" , "have an affair?" , "Slip up" , "Go astray" , "Boob" .)