The most common and most likely answer to this crossword clue is the 6 plus 8 letter word AGATHA CHRISTIE
I've seen this crossword clue in The Daily Telegraph
A
G
A
T
H
A
C
H
R
I
S
T
I
E
More clues leading to the result AGATHA CHRISTIE
- One who wrote of a gun held initially by a serial killer
- Mystery writer chewing the rag at Ischia
- A writer’s saga: thrice a hit novel
- Writer of primarily heretical articles found in new atheistic rag
- Complex, rich saga that is abridged by English writer
- Story that has no beginning, that has no end — Jesus, that is a writer!
- Novel is a right cheat, with a leading author
- & 16d A charge that is ‘fabricated’, I admitted
- Crime writer's novel has tragic hate consuming one
- Author wants this chair carved in stone
Buddy explains!
The straight part
We know that "Writer" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case writer = agatha christie.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.