Name by which Ludwig van Beethoven's Symphony No 3 in E Flat Major, Op 55 is known (6)
I believe the answer is:
eroica
(Other definitions for eroica that I've seen before include "noted work" , "19's 3rd 16" , "Name of Beethoven's Third symphony" , "Title of Beethoven's 3rd" , "Name given to Beethoven's Symphony No 3" .)