n. 瓶空, (火箭燃料箱中的)气隙, 损耗

[经] 缺量, 漏损

[ noun ]
the amount that a container (as a wine bottle or tank) lacks of being full
<noun.quantity>

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