Laid back about English knight’s disclaimer (6)
I believe the answer is:
denial
'disclaimer' is the definition.
(thesaurus)
'laid back about english knight's' is the wordplay.
'back' says the letters should be written backwards.
'about' indicates putting letters inside.
'english' becomes 'e' (abbreviation).
'knight' becomes 'n' (chess).
'laid' reversed gives 'dial'.
'e'+'n'='en'
'dial' enclosing 'en' is 'DENIAL'.
(Other definitions for denial that I've seen before include "Declaration that something is untrue" , "Act of asserting that something alleged is not true" , "Daniel (anag.)" , "Saying it isn't so" , "Rejection of a request" .)