noun
: a tax that is imposed by the federal government and a number of states in the United States primarily as a supplement to and to prevent avoidance of death taxes through gifts of property before death inter vivos and that is assessed to the donor at graduated rates somewhat below death-tax rates and sometimes on a tax base which is cumulative during the lifetime of the donor with the tax rate on gifts in any one year being dependent upon the total amount of all prior gifts since adoption of the law