This meaning refers to a strong cylindrical container, usually wider in the middle and traditionally made from wooden staves.
The cellar contained several wooden casks.
Water was stored in a large cask.
This meaning refers specifically to a barrel in which alcoholic drinks are stored, conditioned, or aged.
The whisky matured in an oak cask.
The brewery serves beer directly from the cask.
This use refers to a quantity measured by the contents of a cask.
The merchant ordered a cask of wine.
They exported several casks of rum.
