Took legal action against endless leather (4)
I believe the answer is:
sued
'took legal action against' is the definition.
(I've seen this before)
'endless leather' is the wordplay.
'endless' means to remove the last letter.
'leather' becomes 'suede' (suede is a kind of leather).
'suede' with its last letter removed is 'SUED'.
(Other definitions for sued that I've seen before include "Prosecuted" , "taken to court" , "Brought an action against" , "Started legal proceedings against (someone)" , "Took legal action against" .)