Tricorne that's corny? (3,3)
I believe the answer is:
old hat
This clue might be a double definition.
'tricorne' is the first definition.
Both the answer and definition are singular nouns.
Perhaps they are linked in a way I don't understand?
'corny?' is the second definition.
(thesaurus)
'that's' is the link.
Can you help me to learn more?
(Other definitions for old hat that I've seen before include "Past its prime, like ancient headgear" , "Victorian Balmoral could be" , "Out of date like ancient headgear" , "bonnet that's somewhat battered?" , "Something tediously familiar" .)