Honoured king broken, he had to admit defeat finally (8)
I believe the answer is:
knighted
'honoured' is the definition.
(given a knighthood)
'king broken he had to admit defeat finally' is the wordplay.
'broken' indicates anagramming the letters.
'he had' becomes 'he'd'.
'to admit' indicates putting letters inside.
'finally' indicates one should take the final letters.
The last letter of 'defeat' is 't'.
'king' anagrammed gives 'knig'.
'knig'+'hed'='knighed'
'knighed' going around 't' is 'KNIGHTED'.
(Other definitions for knighted that I've seen before include "Given a title" , "Made a Sir" , "Given an honour" , "Dubbed 'Sir'" .)