Liquid amount lost in storage

• Result of liquid loss in a cask
• The amount that a container (as a wine bottle or tank) lacks of being full
• Empty portion of a bottle
• Unfilled part of a wine cask
• Liquid lost from a container
• Amount lacking to make a full cask
• Amount needed to fill a cask

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
"amount by which a cask or bottle falls short of being full," late 15c., from Anglo-French ulliage (early 14c.), Anglo-Latin oliagium (late 13c.), Old French ouillage , from ouiller "to fill up (a barrel) to the bung," literally "to fill to the eye," from ...

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Ullage \Ul"lage\ (?; 48), n. [OF. eullage, ovillage, the filling up of a cask, fr. ouillier, oillier, euillier, to fill a wine cask; properly, to add oil to prevent evaporation, as to a flask that is nearly full, fr. OF. oile oil. See Oil .] (Com.) The ...