Christmas drink, lacking any good, gets one sent up (6)
I believe the answer is:
eggnog
'christmas drink' is the definition.
(I've seen this before)
'lacking any good gets one sent up' is the wordplay.
I cannot really understand how this works, but
'lacking' could be 'no' (eg lacking money means with no money) and 'no' is located in the answer.
'good' could be 'g' (abbreviation) and 'g' is present in the answer.
The remaining letters 'egg' is a valid word 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 eggnog that I've seen before include "Punch comprising cream and other farm produce" , "A punch for bedtime, perhaps" , "Drink similar to advocaat" , "Drink (milk punch)" , "Dairy-based drink" .)