Vast containers? (4)
I believe the answer is:
vats
'containers?' is the definition.
(vat is a kind of container)
'vast' is the wordplay.
'vast' can be anagrammed to 'VATS'.
Though, I'm not clear how the anagram is indicated.
Can you help me to learn more?
(Other definitions for vats that I've seen before include "Large casks" , "Tanks" , "Brewing vessels" , "Large tubs" , "Large open vessels for storing liquids" .)