Entry 1 sense Webster, 1913 ullage /(ŭl"lā̇j; 48)/ · ul·lage · IPA /ˈʌl.ɪd͡ʒ/ 01 n. The amount which a vessel, as a cask, of liquor lacks of being full; wantage; deficiency. 1. The amount which a vessel, as a cask, of liquor lacks of being full; wantage; deficiency.(Com.)