Old story of Achilles' heel? (6)
I believe the answer is:
legend
'old story' is the definition.
(traditional story)
'achilles' heel?' is the wordplay.
'achilles'' becomes 'leg' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'heel?' becomes 'end' (I've seen this in another clue).
'leg'+'end'='LEGEND'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for legend that I've seen before include "Ancient story" , "Caption; very well known" , "Story about mytical beings" , "Story of mythical beings or events" , "The story of Achilles, say" .)