Bless with oil (6)
I believe the answer is:
anoint
'bless with oil' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for anoint that I've seen before include "Consecrate with holy oil" , "Consecrate with oil or ointment" , "Consecrate with sacred oils" , "Apply consecrated oil to" , "Bless with holy oil" .)