The most common and most likely answer to this crossword clue is the 7 letter word BEOWULF
I've seen this crossword clue in The Times
B
E
O
W
U
L
F
More clues leading to the result BEOWULF
- Bard’s beginning revision of woeful epic poem
- Anonymous old poem book lifted illness misery
- Primarily, big English opus wherein Unferð loses face?
- Book with translation of woeful poem
- An old tale in book, the return of illness and misery
- Epic poem in book, woeful novel
- Book review: “Woeful, it’s a really hard read“
Buddy explains!
The straight part
We know that "Anonymous old poem" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case anonymous old poem = beowulf.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.