With him, a fast start would be a sheer accident (4)
I believe the answer is:
luke
'with him a fast start would be a sheer accident' is the definition.
The definition suggests a singular noun which matches the answer.
This is all the clue.
Can you help me to learn more?
(Other definitions for luke that I've seen before include "Gospel writer" , "One of the Apostles" , "Third NT book" , "Matthew, Mark, - - and John" , "One of the Gospels" .)