Hopeless sob implies upset (10)
I believe the answer is:
impossible
'hopeless' is the definition.
(associated in meaning)
'sob implies upset' is the wordplay.
'upset' is an anagram indicator.
'sob'+'implies'='sobimplies'
'sobimplies' is an anagram of 'IMPOSSIBLE'.
(Other definitions for impossible that I've seen before include "See 10" , "Hopeless" , "Not able to take place" , "some kind of mission" , "See 14 down" .)