Definitions for "T-Bill"
A non-interest-bearing discount security issued by governments to finance national debt. The return to the investor at maturity is the difference between the price paid and the face value at maturity. T-bills are differentiated by maturity into 91 days, 181 days and 364 days.
A security issued by the U.S. Government with a maturity of less than one year. T-bills are sold at a discount from par, and therefore, do not bear a fixed interest rate. Treasury bonds mature in more than ten years from their issue date. Treasury notes mature in more than a year, but not more than ten years from their issue date.
the basis for interest rates for many federal and private (alternative) student loans.