Source of oil for an articulated truck (3)
I believe the answer is:
rig
'an articulated truck' is the definition.
(I know that semi-trailer truck can be written as rig)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for rig that I've seen before include "Fit with sails and tackling" , "Outfit of clothes or oil-drilling platform" , "Accoutre" , "Manipulate fraudulently" , "Masts, spars and sails on a vessel" .)