Oil-drilling machinery (3)
I believe the answer is:
rig
'oil-drilling machinery' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for rig that I've seen before include "Provide with clothes - for oil well?" , "Oil platform" , "Manipulate; (oil exploration) apparatus" , "Set up; equipment" , "Oil derrick" .)