Hate little drinks being upending into river (7)
I believe the answer is:
despise
'hate' is the definition.
(I know that despise is a more specific form of the action hate)
'little drinks being upending into river' is the wordplay.
'little drinks' becomes 'sips' (I've seen this in another clue).
'being upending' says the letters should be written in reverse.
'into' means one lot of letters goes inside another.
'river' becomes 'Dee' (River Dee).
'sips' back-to-front is 'spis'.
'spis' placed into 'dee' is 'DESPISE'.
(Other definitions for despise that I've seen before include "Scorn; loathe" , "Feel contempt for; scorn" , "Have contempt for, regard as low" , "Look down on with disdain" , "Loathe, look down on" .)