The most common and most likely answer to this crossword clue is the 5 plus 4 letter word ROALD DAHL
I've seen this crossword clue in Financial Times
R
O
A
L
D
D
A
H
L
More clues leading to the result ROALD DAHL
- Learner pulled into street, kept turning left, source of children’s amusement
- Author, seeing learner in street, had turned left
- Way round lake with boy returning holding hands, at first
- Author had a droll style
- Author’s line used in course had misdirected learner
- One line written during course had repelled another 29
- Liberal Lord had a bit of luck – today’s his day
Buddy explains!

The straight part
We know that "Author" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case author = roald dahl.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.