Chap's mistake to change direction at the end (5)
I believe the answer is:
errol
'chap's' is the definition.
'mistake to change direction at the end' is the wordplay.
I cannot really understand how this works, but
'mistake' could be 'err' ('err' can be a synonym of 'mistake') and 'err' is present in the answer.
'direction' could be 'l' and 'l' is found in the answer.
A single letter 'o' remains which might be clued in a way I don't see.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for errol that I've seen before include "-- Flynn, Hollywood actor" , "- - Flynn, film star" , "- Flynn, twentieth century film actor" , "- Flynn, US film actor" , "Old film star" .)