is a rate (as of taxation) expressed in mills per dollar.
Factor applied to the assessed, a.k.a, taxable, valuation of real or personal tangible property to produce tax revenue. A mill is defined as one-tenth of a percent or one-tenth of a cent (0.1¢) in cash terms.
a rate applied to a property's taxable value to determine what property tax is due. When used with ad valorem (property) taxes, the rate expresses the dollars of tax per one thousand dollars of taxable value (i.e., a 5 mill tax on $1,000 equals $5.00).