oleum

noun

ole·​um ˈō-lē-əm 

1

plural olea ˈō-lē-ə  : oil

2

plural oleums : a heavy oily strongly corrosive solution of sulfur trioxide in anhydrous sulfuric acid

Word History

Etymology

Latin, olive oil — more at oil

First Known Use

circa 1823, in the meaning defined at sense 1

Medical Definition

oleum

noun

ole·​um ˈō-lē-əm 

plural olea -lē-ə 

: oil sense 1