The most common and most likely answer to this crossword clue is the 6 letter word ASIMOV
I've seen this crossword clue in The Guardian
A
S
I
M
O
V
More clues leading to the result ASIMOV
- Stasi moved to hold famous author
- US writer’s visa returned, opened by medic
- US writer omitting name of apostle in version of Bible
- Writer like Self to change position, renouncing drug
- Writer Virginia, receiving honour, is coming back
- SF writer announced when I’m leaving
- Like one film that is forgotten
- He wrote because one needs second volume
- SF writer acts like one with film that is withdrawn
- Version of bible having nameless apostle inserted by writer
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 = asimov.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.