Took a risk housing priest about to be thrown off course (8)
I believe the answer is:
derailed
'be thrown off course' is the definition.
(I've seen this in another clue)
'took a risk housing priest about' is the wordplay.
'took a risk' becomes 'dared' (I've seen this before).
'housing' means one lot of letters goes inside another.
'priest' becomes 'eli' (biblical figure).
'about' says the letters should be written in reverse.
'dared' going around 'eli' is 'deliared'.
'deliared' in reverse letter order is 'DERAILED'.
'to' acts as a link.
(Other definitions for derailed that I've seen before include "To be off the track" , "Forced off the tracks" .)