The setter's stomach rejects large drink (6)
I believe the answer is:
imbibe
'drink' is the definition.
(synonyms)
'the setter's stomach rejects large' is the wordplay.
'the setter's' becomes 'im' (I've seen this in other clues).
'stomach' becomes 'bible' (informal name for a part of a ruminant's stomach).
'rejects' indicates named letters should be taken away.
'large' becomes 'l'.
'bible' with 'l' removed is 'bibe'.
'im'+'bibe'='IMBIBE'
(Other definitions for imbibe that I've seen before include "Tope" , "Drink in - assimilate" , "Drink or absorb into mind" , "Drink (alcohol)" , "Take in (with one's mother's milk?)" .)