Atarax ata·rax uncommon noun 1. a drug (trade names Atarax and Vistaril) used as a tranquilizer to treat anxiety and motion sickness Synonymshydroxyzine hydrochloridehydroxyzineVistaril Related words Word family ataraxiaataraxicataraxis Broader terms minor tranquilizer WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.