A container (3)
'a container' is the definition.
(I know that pot is a type of container)
This is all the clue.
(Other definitions for pot that I've seen before include "Grass" , "Street name for marijuana" , "Slangy cannabis" , "Preserve; drug" , "Somewhere to go" .)
'a container' is the definition.
(jar is a kind of container)
This is the entire clue.
(Other definitions for jar that I've seen before include "Container; be incongruous" , "Wide-mouthed vessel" , "Storage container" , "Cylindrical container as for jam" , "Shock; container" .)