1DHC [transitive] British English
to wash something by pouring a lot of water over it or into it
swill something away/down/out
Get a bucket to swill the yard down.
2 [intransitive and transitive]
if a liquid swills around or you swill it around, it moves around something
He swilled his brandy gently round his glass.
3DFD [transitive] also swill down informal
to drink something in large amounts:
He does nothing but swill beer all day.