Drink with a girl and get firmly established (3,2)
I believe the answer is:
dig in
'get firmly established' is the definition.
I can't judge whether this defines the answer.
'drink with a girl' is the wordplay.
'drink' becomes 'gin' (gin is a kind of drink).
'with' means one lot of letters go next to another.
'a girl' becomes 'di' (**).
'gin' put after 'di' is 'DIG IN'.
'and' is the link.
Can you help me to learn more?
(Other definitions for dig in that I've seen before include "Start to eat" , "Start to scoff" , "Begin eating (informal)" , "Start eating (informal)" , "Begin eating heartily" .)