Pardon the jargon.
TD stands for Trust Deeds, AKA mortgages in most states. They are a promissory note secured (collateralized) by a trust deed, a claim on a property if the note is not paid.
Usually institutions like banks hold the first deed, and investors with an appetite for risk and high return can piggybank behind a 1st TD. The danger is that in the event of foreclosure, the 1st gets paid off first with the proceeds of the foreclosure sale, and the 2d TD gets any residual. Commonly, the 2d TD holder can protect his investment only by assuming the 1st TD loan or paying it off.
