ampersat UK /ˈæm.pə.sæt/US /ˈæm.pɚ.sæt/ noun1 •(rare) The at sign (@).[…]there are users out there on the Internet right now who think that they possess an e-mail address containing neither an at-sign (@ often known as an "ampersat") nor a domain name. — 2000 formsampersats