clean price

The clean price Pᶜ of α bond at a given reference date T regarded as the settlement date of a bond purchase transaction is defined in terms of the bond's
dirty price Pᵈ as:
Pᶜ = Pᵈ - I
where I is the interest amount (based on a notional of 100) that has been accrued until T during the coupon accrual period containing T