Loathing to break thread (6)
I believe the answer is:
hatred
'loathing' is the definition.
(I've seen this in another clue)
'break thread' is the wordplay.
'break' is an anagram indicator.
'thread' anagrammed gives 'HATRED'.
'to' acts as a link.
(Other definitions for hatred that I've seen before include "hostility" , "Detestation, loathing" , "Dearth (anag)" , "Extreme dislike and enmity" , "Abhorrence, detestation" .)