Not drinking from the little cup at all (8)
I believe the answer is:
teetotal
'all' is the definition.
Both the answer and definition are adjectives. Maybe you can see an association between them that I don't see?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for teetotal that I've seen before include "Never drinking alcohol" , "Sworn off alcohol" , "Abstinent from alcohol" , "Taking no alcohol" , "On the wagon" .)