Tense following refusal. Little drink? Absolutely (3,4)
I believe the answer is:
not half
'absolutely' is the definition.
(I've seen this before)
'tense following refusal little drink?' is the wordplay.
'tense' becomes 't' (abbreviation used in many dictionaries).
'following' says to put letters next to each other.
'refusal' becomes 'no'.
'little drink?' becomes 'half' (I've seen this before).
't' put after 'no' is 'not'.
'not'+'half'='NOT HALF'
(Other definitions for not half that I've seen before include "A full pint?" , "Very much (but less than 50%)!" , "less than fifty per cent" , "I warmly agree!" , "Oh, yes!" .)