Addition to the family calls for a drink (3)
I believe the answer is:
tot
'a drink' is the definition.
(a small alcoholic drink)
'addition to the family' is the wordplay.
I cannot really understand how this works, but
'to' is present in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'calls for' acts as a link.
Can you help me to learn more?
(Other definitions for tot that I've seen before include "Aggregate for infant" , "Small amount of spirits" , "Add - youngster - dram" , "Nip" , "Small drink of spirits" .)