Disorganised bartender I cast out (14)
I believe the answer is:
scatterbrained
'disorganised' is the definition.
(I've seen this before)
'bartender i cast out' is the wordplay.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'bartender'+'i'+'cast'='bartendericast'
'bartendericast' is an anagram of 'SCATTERBRAINED'.
(Other definitions for scatterbrained that I've seen before include "Empty-headed" , "Careless" , "Disorganised and unable to concentrate" , "Inattentive" , "Unfocused" .)