Oil company with toy trucks (4)
I believe the answer is:
hess
'oil company with toy trucks' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for hess that I've seen before include "leading Nazi" , "Pianist Myra, Nazi Rudolf ---" , "Famous pianist" , "Rudolf ..., Nazi leader imprisoned at Spandau" , "Cite as evidence" .)