Help secured by knights, say, yet to win (6)
I believe the answer is:
maiden
'yet to win' is the definition.
I can't judge whether this definition defines the answer.
'help secured by knights say' is the wordplay.
'help' becomes 'aid' (synonyms).
'secured by' indicates putting letters inside (inserted letters are held or secured).
'knights say' becomes 'men' (knight is a kind of man).
'aid' inserted inside 'men' is 'MAIDEN'.
Can you help me to learn more?
(Other definitions for maiden that I've seen before include "No-score over" , "Single" , "Female" , "horse that's never won" , "First (speech)" .)