Is resentful of things (7)
I believe the answer is:
objects
'things' is the definition.
(I've seen this in another clue)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for objects that I've seen before include "Articles; aims" , "Expresses opposition" , "Opposes" , "Doesn't agree" , "Material things" .)