Cliches etc thus translated to cover new section (9)
I believe the answer is:
'cliches' is the definition.
(as in an old chestnut)
I don't understand the rest of the clue.
(Other definitions for chestnuts that I've seen before include "Tree fruits called conkers - some are edible" , "often retold stories" , "horses" , "Common tree-fruits, sometimes roasted" .)