A halter needs a ring in the nose (5)
I believe the answer is:
noose
'a halter' is the definition.
(I've seen this in another clue)
'a ring in the nose' is the wordplay.
'a ring' becomes 'o' (letter resembling a ring).
'in' indicates putting letters inside.
'o' going within 'nose' is 'NOOSE'.
'needs' is the link.
(Other definitions for noose that I've seen before include "Circular loop" , "Bond" , "it could endanger your life" , "Fatal device" , "form of punishment" .)