ullage Meaning, Definition & Usage

  1. noun the amount that a container (as a wine bottle or tank) lacks of being full

WordNet

Ul"lage noun
Etymology
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.
Definitions
  1. (Com.) The amount which a vessel, as a cask, of liquor lacks of being full; wantage; deficiency.

Webster 1913