the amount by which the contents fall short of filling a container, as a cask or bottle.
the quantity of wine, liquor, or the like, remaining in a container that has lost part of its contents by evaporation, leakage, or use.
Rocketry. the volume of a loaded tank of liquid propellant in excess of the volume of the propellant; the space provided for thermal expansion of the propellant and the accumulation of gases evolved from it.
1400-50;late Middle English < Anglo-Frenchulliage;Old Frenchouillage, (h)eullage wine needed to fill a cask, equivalent to (a)ouill(er) to fill (a cask) (derivative of ouil eye, hole < Latinoculus) + -age-age
"amount by which a cask or bottle falls short of being full," late 15c., from Anglo-Fr. ulliage (early 14c.), Anglo-L. oliagium (late 13c.), O.Fr. ouillage, from ouiller "to fill up (a barrel) to the bung," lit. "to fill to the eye," from ueil "eye," from L. ochulus.