oleum
ole.um \'o--le--*m\ \-le--*\ n or olea or oleums [L - more at OIL] pl 1: OIL pl 2: a heavy oily strongly corrosive solution of sulfur trioxide in anhydrous sulfuric acid
ole.um \'o--le--*m\ \-le--*\ n or olea or oleums [L - more at OIL] pl 1: OIL pl 2: a heavy oily strongly corrosive solution of sulfur trioxide in anhydrous sulfuric acid