Tradition plays role (4)
I believe the answer is:
lore
'tradition' is the definition.
(I've seen this in another clue)
'plays role' is the wordplay.
'plays' indicates an anagram.
'role' with letters rearranged gives 'LORE'.
(Other definitions for lore that I've seen before include "Traditional belief" , "Ancient learning" , "Wisdom" , "Folk myths" , "Mythology" .)