Beethoven's Third (6)
I believe the answer is:
eroica
'beethoven's third' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for eroica that I've seen before include "Name of Beethoven's Third symphony" , "Beethoven piece" , "noted work" , "Name of a Beethoven symphony" , "Title of Beethoven's 3rd" .)