A neurotic trembled, wanting liqueur (9)
I believe the answer is:
cointreau
'liqueur' is the definition.
(I've seen this in another clue)
'a neurotic trembled' is the wordplay.
'trembled' is an anagram indicator.
'a'+'neurotic'='aneurotic'
'aneurotic' with letters rearranged gives 'COINTREAU'.
'wanting' is the link.
(Other definitions for cointreau that I've seen before include "Sweet orange-flavoured colourless liqueur" , "A sweet orange-flavoured liqueur for cautioner" , "Alcoholic drink" , "Orange liqueur" .)