Note what doctor half said about cocktail (6)
I believe the answer is:
mimosa
'cocktail' is the definition.
(I've seen this before)
'note what doctor half said about' is the wordplay.
I cannot really see how this works, but
'note' could be 'mi' (as in 'do re mi') and 'mi' is found within the answer.
'doctor' could be 'mo' (medical officer) and 'mo' is found in the answer.
'about' could be 'a' (abbreviation in Chambers) and 'a' is located in the answer.
A single letter 's' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for mimosa that I've seen before include "Buck's Fizz" , "Shrub - I'm Amos (anag)" , "Plant genus popularly extended to the Acacia" , "Sensitive tree or shrub with globular clusters of yellow flowers" , "Tree with scented clustered flowers" .)