Uncouth bride collapses, having drunk two litres (3-4)
I believe the answer is:
ill-bred
'uncouth' is the definition.
(I've seen this before)
'bride collapses having drunk two litres' is the wordplay.
'two litres' means two replacements for 'litre'.
'collapses' is an anagram indicator.
'having drunk' indicates putting letters inside.
'litre' becomes 'L' (abbreviation).
'litre' becomes 'L' (abbreviation).
'bride' is an anagram of 'ibred'.
'l'+'l'='ll'
'ibred' going around 'll' is 'ILL-BRED'.
(Other definitions for ill-bred that I've seen before include "Uncouth" , "Unrefined" , "Boorish" , "Badly raised, having bad manners" , "Ill-mannered, badly reared" .)