From Longman Business Dictionarydiscretionary trustdisˈcretionary ˌtrustLAWFINANCE1[countable] a trust whose managers are allowed to decide the best way of managing the trust and the best way of sharing its income and capitalA discretionary trust fund was set up to help disabled people living at home.2[countable] an arrangement for leaving money to someone in a TRUST after you die, where the person managing the trust decides when to make payments, how much to pay etcIf you are worried about your relative not being able to manage money, you could leave a sum of money on discretionary trust. → trust