Complaint one twit receives over a bit of a pint (5,5)
I believe the answer is:
fluid ounce
'a bit of a pint' is the definition.
('fluid ounce' is part of 'pint')
'complaint one twit receives over' is the wordplay.
'complaint one' becomes 'flui' (I can't justify this - if you can you should believe this answer much more).
'twit' becomes 'dunce'.
'receives' means one lot of letters goes inside another.
'over' becomes 'o' (cricket abbreviation).
'dunce' enclosing 'o' is 'dounce'.
'flui'+'dounce'='FLUID OUNCE'
(Other definitions for fluid ounce that I've seen before include "volume of water?" , "a little liquid" .)