German dons drunk brandy with ale mostly (2,3,5)
I believe the answer is:
by and large
'mostly' is the definition.
('by and large' can be a synonym of 'mostly')
'german dons drunk brandy with ale' is the wordplay.
I cannot quite see how this works, but
'german' could be 'g' (abbreviation) and 'g' is found in the answer.
'with' could be 'and' (I've seen this before) and 'and' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for by and large that I've seen before include "for the most part" , "All things considered" , "Speaking generally" , "On the whole" , "In general" .)