Stand for leader of England with muscular back (6)
I believe the answer is:
denote
'stand for' is the definition.
(thesaurus)
'leader of england with muscular back' is the wordplay.
'leader of' indicates taking the first letters.
'with' says to put letters next to each other.
'muscular' becomes 'toned' (I've seen this before).
'back' shows that the letters should be reversed in order.
The initial letter of 'england' is 'e'.
'toned' back-to-front is 'denot'.
'e' after 'denot' is 'DENOTE'.
(Other definitions for denote that I've seen before include "Indicate, signify" , "Be an indication of" , "Stand as symbol for" , "Need to (anag) - indicate" , "Designate" .)