Containers may be bust (4)
I believe the answer is:
tubs
'containers' is the definition.
(tub is a kind of container)
'may be bust' is the wordplay.
'may' is an anagram indicator (I've seen 'might' mean this (I've seen this in other clues)).
'bust' anagrammed gives 'TUBS'.
(Other definitions for tubs that I've seen before include "Awkwardly-handling boats" , "Barrels" , "Gurnard" .)