Definitions
1.nounIn a wine bottle, the empty space between the cork and the top of the wine.
2.nounIn a cask or barrel, the empty space, occupied by air, that is created by not completely filling the cask or barrel, or through spillage.
3.nounThe topping-up of such a barrel with fresh wine.
4.nounIn an industrial setting, the empty space in a tank, such as for fuel.
5.verbTo gauge the amount of empty space between the top of a cask and the level of liquid inside it.