Stop pouring wine, oddly, around empty hole (4)
I believe the answer is:
when
'stop pouring' is the definition.
(said to ask someone to stop pouring a drink)
'wine oddly around empty hole' is the wordplay.
'oddly' means one should take alternating letters (letters in the odd-numbered positions are used).
'around' is an insertion indicator.
'empty' says to hollow out the word (remove centre letters).
'hole' with its centre removed is 'he'.
The alternate letters of 'wine' are 'wn'.
'wn' going around 'he' is 'WHEN'.
(Other definitions for when that I've seen before include "Say it when you''ve had enough" , "Over what period?" , "At what time?" , "stop pouring the drink" , "As soon as" .)