Spin intros to traditional Horkstow Grange in the dark (5)
I believe the answer is:
night
'the dark' is the definition.
(night is a kind of dark)
'spin intros to traditional horkstow grange in' is the wordplay.
'spin' says the letters should be written backwards.
'intros to' indicates taking the first letters.
The initial letters of 'traditional horkstow grange' is 'thg'.
'thg'+'in'='thgin'
'thgin' back-to-front is 'NIGHT'.
(Other definitions for night that I've seen before include "Darkness; see you in the morning" , "Time without 10" , "follow-up to 16 [TWILIGHT]" , "death" , "End of the day" .)