Webster's Revised Unabridged Dictionary · 1913

Ethionic

Ethionic , adjective

[Ethyl + thionic.]

(Chemistry) Pertaining to, derived from, or designating, an acid so called.
Collocations (1)
Ethionic acid (Chemistry) , a liquid derivative of ethylsulphuric and sulphuric (thionic) acids, obtained by the action of sulphur trioxide on absolute alcohol.