Fish going round in bowls (6)
I believe the answer is:
basins
'bowls' is the definition.
('basin' can be a synonym of 'bowl')
'fish going round in' is the wordplay.
'fish' becomes 'bass' (bass is a kind of fish).
'going round' indicates putting letters inside (some letters go around others).
'bass' going around 'in' is 'BASINS'.
(Other definitions for basins that I've seen before include "Bowl-shaped vessels" , "Sinks" .)