38 The Electrochemical Society Interface â¢ Spring 2007. Whatâs an Ionic Liquid? by Keith E. Johnson. âWhen I use a word,â Humpty Dumpty said, in rather a scornful tone, âit means just what I choose it to mean â neither more nor less.â. âThe question is,â said Alice, âwhether you can make words mean so many different things.â.