Too many drinks, we figure (4)
I believe the answer is:
nine
'figure' is the definition.
(a number of figure)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for nine that I've seen before include "'Possession is... points of the law'" , "One over the eight" , "One more than fourteen across" , "A stitch in time saves them" , "Cat's lives? - the next clue?" .)