Drink to excess and knock over vessel on right-hand side (4)
I believe the answer is:
tope
'drink to excess' is the definition.
(I've seen this before)
'knock over vessel on right-hand side' is the wordplay.
'knock over' says the letters should be written backwards.
'vessel' becomes 'pot' (type of container).
'on right hand side' becomes 'e' (I am not sure about this - if you are sure you should believe this answer much more).
'pot' back-to-front is 'top'.
'top'+'e'='TOPE'
'and' is the link.
Can you help me to learn more?
(Other definitions for tope that I've seen before include "What habitual drinkers do" , "Drink a lot like poet" , "Small grey requiem shark" , "plantation?" , "Drink hard regularly" .)