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Webster 1913 Edition

(ŭl′lā̍j; 48)

Noun.

[OF.

eullage

ouillage

, 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

(Com.)

The amount which a vessel, as a cask, of liquor lacks of being full; wantage; deficiency.

Noun.

In commerce, the wantage of casks of liquor, or what a cask wants of being full.

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
The topping-up of such a barrel with fresh wine
In an industrial setting, the empty space in a tank, such as for fuel

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.