Occasional alcoholic, I do sip entire upended bottles (8)
I believe the answer is:
episodic
'occasional' is the definition.
(I know that occasional can be written as episodic)
'alcoholic i do sip entire upended bottles' is the wordplay.
'bottles' says the answer is hidden in the clue (bottling is a kind of containing).
'upended' says the letters should be written in reverse (in a down clue, letters go up).
'cidosipe' is hidden in the letters of 'alcoholic i do sip entire'.
'cidosipe' reversed gives 'EPISODIC'.
(Other definitions for episodic that I've seen before include "Occurring irregularly - is copied accordingly" , "Sporadic" , "Serialised" , "Arranged as a series of incidents" , "Intermittent" .)