One stopping to get an item of tack (6)
I believe the answer is:
halter
I believe this clue is a double definition.
'one stopping' is the first definition.
(someone halting or stopping)
'an item of tack' is the second definition.
(part of a horse's tack)
'to get' is the link.
(Other definitions for halter that I've seen before include "one that pulls up?" , "Rope for leading animals" , "Rope for leading animal" , "Dress strap round neck" , "Hangman's rope" .)