What is "ethylsulphuric acid"

Ethylsulphuric \Eth`yl*sul*phu"ric\a. (Chem.) Pertaining to, or containing, ethyl and sulphuric acid.

Ethylsulphuric acid (Chem.), an acid sulphate of ethyl, H.C2H5.SO4, produced as a thick liquid by the action of sulphiric acid on alcohol. It appears to be the active catalytic agent in the process of etherification.

n. (context organic compound English) The partial ethyl ester of sulfuric acid, H.C₂H₅.SO₄, produced as a thick liquid by the action of sulphuric acid on alcohol