Income tax return is a commonly used term that refers to the document that taxpayers fill out and submit to the government to report their income taxes. However, there are several synonyms that can be used for this term. One of these is tax form, which refers to any document that taxpayers need to complete and submit to the tax authorities. Another synonym is tax return, which specifically refers to the document that taxpayers fill out to report their tax liabilities. Other synonyms for income tax return include tax filing, tax declaration, and tax refund application. These terms all refer to the process of reporting and paying taxes to the government.