Rum cocktail during work causes trouble (7)
I believe the answer is:
turmoil
'trouble' is the definition.
(thesaurus)
'rum cocktail during work' is the wordplay.
'cocktail' is an anagram indicator.
'during' is an insertion indicator.
'work' becomes 'toil' (toiling is a kind of working).
'rum' with letters rearranged gives 'urm'.
'urm' put inside 'toil' is 'TURMOIL'.
'causes' is the link.
(Other definitions for turmoil that I've seen before include "Chaos" , "Agitation, din, bustle" , "Unrest - upheaval" , "Uproar" , "Pandemonium" .)