Greek leg-end in Greek legend? (8,4)
I believe the answer is:
achilles heel
'greek legend?' is the definition.
The definition suggests a singular noun which matches the answer.
'greek leg-end' is the wordplay.
I cannot really understand how this works, but
'greek' could be 'achilles' (I have seen 'Famous Greek' mean 'achilles' so perhaps 'greek' could also mean 'achilles') and 'achilles' is present in the answer.
'end' could be 'heel' (heel can mean the end of something) and 'heel' is located in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'in' is the link.
Can you help me to learn more?
(Other definitions for achilles heel that I've seen before include "A chink in the armour" , "Personal weak spot" , "Vulnerable part" , "Person's vulnerable weakness" , "One's most vulnerable spot" .)