Lady Bert is pouring a drink for (7)
I believe the answer is:
sherbet
'drink for' is the definition.
'sherbet' can be an answer for 'drink' (I've seen this before). I'm unsure of the 'for' bit.
'lady bert is pouring a' is the wordplay.
I cannot quite understand how this works, but
'lady' could be 'sher' and 'sher' is found in the answer.
'is' could be 'be' and 'be' is found in the answer.
A single letter 't' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for sherbet that I've seen before include "Fizzy stuff" , "Sweet fizzy, fruity, drink" , "A fizzy drink, a fruit drink" , "Australian beer" , "iced food" .)