Source of alcohol has addled brain after I'm stood up (7)
I believe the answer is:
minibar
'source of alcohol' is the definition.
(a minibar stocks alcohol)
'addled brain after i'm stood up' is the wordplay.
'addled' is an anagram indicator.
'after' is a charade indicator (letters next to each other).
'stood up' says the letters should be written backwards (in a down clue, letters go up).
'im' reversed gives 'mi'.
'brain' with letters rearranged gives 'nibar'.
'nibar' put after 'mi' is 'MINIBAR'.
'has' acts as a link.
(Other definitions for minibar that I've seen before include "Hotel bedroom fridge" , "Source of hotel room drinks" , "Hotel room chiller?" , "Hotel room fridge" , "cooler for hotel guest?" .)