Who's in pub besetting teetotal European? (6)
I believe the answer is:
batter
'who's' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'pub besetting teetotal european?' is the wordplay.
'pub' becomes 'bar' (both are drinking establishments).
'besetting' is an insertion indicator.
'teetotal' becomes 'tt' (abbreviation).
'european?' becomes 'E' (abbreviation e.g. EU).
'tt'+'e'='tte'
'bar' placed around 'tte' is 'BATTER'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for batter that I've seen before include "Strike hard and often" , "Beat heavily" , "Hit hard and often, like cooking mixture" , "Beat - coating used in frying food" , "sportsman" .)