Endless rage, seeing this coat? (3)
I believe the answer is:
fur
'this coat?' is the definition.
(fur is a kind of coat)
'endless rage' is the wordplay.
'endless' means to remove the last letter.
'rage' becomes 'fury' ('fury' can be a synonym of 'rage').
'fury' with its last letter taken off is 'FUR'.
'seeing' is the link.
(Other definitions for fur that I've seen before include "Coating formed on tongue of sick person" , "Hair covering animal's body" , "eg Cat's coat" , "Outer skin of animal with hair attached" , "Animal-skin coat" .)