European knights boasted endlessly about love and honour (7)
I believe the answer is:
ennoble
'honour' is the definition.
(ennobling is a kind of honouring)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for ennoble that I've seen before include "Lend greater dignity to" , "Create" , "Glorify - confer honour upon" , "Glorify - raise to the peerage" , "Elevate with a title" .)