Debt that has a lower chance of being repaid with interest. Toxic debt is toxic to the person or institution that will receive the payments.
This debt generally adheres to one of the following criteria: default rates for the particular debt are in the double digits, more debt is accumulated than what can comfortably be paid back, the interest rates of the obligation are subject to discretionary changes. Any debt could potentially be considered "toxic," if it imposes harm onto the financial position of the holder.
So again, as I've said multiple times, Elite has no toxic debt. They have paid for ADT trials by selling shares for cash. Bonds issued for their facility are not toxic debt.