ULLAGE
ullage
(noun) the amount that a container (as a wine bottle or tank) lacks of being full
Source: WordNet® 3.1
Etymology
Noun
ullage (countable and uncountable, plural ullages)
In a wine bottle, the empty space between the cork and the top of the wine.
In a cask or barrel, the empty space, occupied by air, that is created by not completely filling the cask or barrel, or through spillage.
The topping-up of such a barrel with fresh wine.
In an industrial setting, the empty space in a tank, such as for fuel.
Verb
ullage (third-person singular simple present ullages, present participle ullaging, simple past and past participle ullaged)
To gauge the amount of empty space between the top of a cask and the level of liquid inside it.
Source: Wiktionary
Ul"lage (; 48), n. Etym: [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.)
Definition: The amount which a vessel, as a cask, of liquor lacks of being
full; wantage; deficiency.
Source: Webster’s Unabridged Dictionary 1913 Edition