Such a drink needn't be frothy (5)
I believe the answer is:
heady
'be frothy' is the definition.
(thesaurus)
'such a drink needn't' is the wordplay.
I cannot quite see how this works, but
'a' is present in the answer.
The remaining letters 'hedy' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for heady that I've seen before include "Extremely exciting" , "Inebriating" , "Impetuous" , "Potent, intoxicating" .)