Amount needed to make a full cask

• Liquid amount lost in storage
• Amount by which a cask falls short of being full
• Unfilled part of a wine cask
• Empty portion of a bottle
• The amount that a container (as a wine bottle or tank) lacks of being full
• Amount lacking to make a full cask

Wikipedia Word definitions in Wikipedia
Ullage (from the French ouillage ) is a winemaking term that has several meanings but most commonly refers to the headspace of air between wine and the top of the container holding the wine. It can also refer to the process of evaporation that creates the ...

WordNet Word definitions in WordNet
n. the amount that a container (as a wine bottle or tank) lacks of being full