Whine and sob terribly — can this bring luck to one of couple? (8)
I believe the answer is:
wishbone
'can this bring luck to one of couple?' is the definition.
(two people might break a wishbone apart)
'whine and sob terribly' is the wordplay.
'and' means one lot of letters go next to another.
'terribly' indicates anagramming the letters.
'whine'+'sob'='whinesob'
'whinesob' is an anagram of 'WISHBONE'.
(Other definitions for wishbone that I've seen before include "Bit of the bird associated with luck" , "Bird-part pulled by two people for luck" , "Part of bird's skeleton" , "Supposedly lucky part of a fowl" , "Forked piece of a chicken" .)