Wiktionary
n. A rate, usually a percentage rate, at which something is taxed.
WordNet
n. rate used to calculate tax liability
Wikipedia
In a tax system, the tax rate is the ratio (usually expressed as a percentage) at which a business or person is taxed. There are several methods used to present a tax rate: statutory, average, marginal, and effective. These rates can also be presented using different definitions applied to a tax base: inclusive and exclusive.
Usage examples of "tax rate".
Charging everyone the same tax rate fulfills the dictionary's definition of 'fair.
Or you could deposit the money in a government-insured bank account, but all interest earned would be assessed at up to a 40-percent maximum tax rate.
Do we agree on a wartime compromise on the immigration laws and the income-tax rate?
The best story receives a maximum of ten talents, the annual tax rate on a home tract.
With vivid memories of the last IRS form I had signed, I agreed sympathetically that a two percent tax rate was a positive outrage, wondering to myself just ,vhat had become of the fiery spirit of American taxpayers over the intervening two hundred years.