Breadcrumb Home > Thesaurus > S Synonyms of surtax Find synonyms for: Noun 1. surtax, supertax, income tax usage: an additional tax on certain kinds of income that has already been taxed Verb 1. surtax, tax usage: levy an extra tax on; "surtax luxury items that cost more than $1,000" WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of surtax (Dictionary) TrendingHere are the facts and trivia that people are buzzing about. Jewish Holidays, 2010-2030 (A.M. 5770-5791) Western Christian Holidays, 2010-2030 12 Steps to a New Year New Year's Resolution to Slim Down? Martin Luther King Speeches Books of the Bible: Old Testament Books in Order ✖ Related Content Daily Word Quiz: supererogatory Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language