Swallow in second branch, broken at the tip (4)
I believe the answer is:
swig
'swallow' is the definition.
(I have seen 'Large swallow' mean 'swig' so perhaps 'swallow' could also mean 'swig')
'second branch broken at the tip' is the wordplay.
I cannot quite see how this works, but
'second' could be 's' (common abbreviation) and 's' is found within the answer.
The remaining letters 'wig' is a valid word which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).
'in' is the link.
Can you help me to learn more?
(Other definitions for swig that I've seen before include "Large draught of drink" , "Glug" , "Drink in large draughts" , "Slug" , "Large gulp from the bottle" .)